Chapter 8 Flashcards
What did people believe about diamond rough thousands of years ago?
It was too sacred to cut or shape, and tampering would destroy its supernatural powers.
Only rulers were allowed to wear diamonds if left undisturbed.
When were diamonds first unearthed and where?
Around 800–600 BC in India.
This marks the beginning of diamond history.
What significant event around 100 AD influenced diamond trade?
Alexander the Great’s expeditions established limited trade between the East and West.
This led to uncut diamonds being set into jewelry by the Romans.
When did diamonds begin to appear in European royal jewelry?
Around 1200 AD.
This indicates the growing importance of diamonds in society.
What was the primary method of diamond cutting in the mid-1300s?
Superficial polishing of the rough diamond.
This involved rubbing rough diamonds on a flat surface with diamond dust mixed with oil or water.
What peak did India’s diamond trading and cutting industry reach?
In the 14th century.
This was a significant period for diamond processing.
What discovery was made by the mid-1400s regarding diamond crystals?
That diamond crystals could be easily split along certain crystal directions, parallel to the cleavage planes.
This process is known as cleaving.
What is the downside of the cleaving process?
It dramatically limits the cutter’s options.
Cleaving allows splitting a diamond crystal into sections along cleavage planes.
True or False: Cleaving is a commonly used technique in diamond cutting today.
False.
Cleaving is rarely used today due to its limitations.
What fueled trade between Asia, Europe, and the Americas in the 15th century?
Increased global exploration
This exploration led to the movement of rough diamonds to Europe.
Which European cities became diamond trading and cutting hubs in the 15th century?
- Venice
- Amsterdam
- Antwerp
- London
Local Jewish communities played a significant role in dominating the industry.
What was happening to the Indian diamond cutting industry in the 15th century?
It gradually waned
This decline coincided with the rise of diamond trading in Europe.
What characterized the 16th century in terms of jewelry and diamond cutting?
Lavish jewelry, extensive use of gems, and technical breakthroughs in diamond cutting
These advancements were significant for the diamond industry.
What was required for precise diamond cutting in the 16th century?
Development of smooth, fast, and continuous rotary motion with minimal vibration
This was essential for improving diamond cutting techniques.
What type of polishing wheels significantly improved diamond cutting in the 16th century?
Cast-iron polishing wheels with continuous rotary motion
These wheels performed better than lead, copper, or steel wheels.
True or False: The Indian diamond cutting industry was thriving in the 15th century.
False
The industry was in decline during this period.
What was Royal Coster Diamonds known for?
A legendary diamond cutting house in Amsterdam in the 1860s
Who commissioned Royal Coster Diamonds to recut the Koh-I-Noor diamond?
Queen Victoria
What famous diamond did Royal Coster Diamonds recut?
The Koh-I-Noor diamond
Fill in the blank: Royal Coster Diamonds was a legendary diamond cutting house in _______ in the 1860s.
Amsterdam
What was the process of diamond sawing before the 20th century?
A long, tedious process of dividing a rough diamond using brass or iron wires coated with olive oil and diamond powder. This method was used beginning in the 17th century.
Who and when invented the motorized diamond saw?
E. Loesser, a Belgian immigrant to the United States. The invention occurred in 1900.
What significant change did the motorized diamond saw introduce?
It made the diamond sawing process fast and accurate.
The saw used a circular blade coated with diamond powder.
How did the motorized diamond saw improve the shaping of rough diamonds?
It allowed cutters to shape the rough in more directions than those following cleavages. This flexibility was a significant improvement over previous methods.
What marked the birth of the modern diamond industry?
The great diamond discoveries in Africa in the late 19th century
This period saw significant changes in the diamond market dynamics.
How did the supply of gem diamonds change in the late 19th century?
The supply of and demand for gem diamonds broadly expanded
New sources of diamonds contributed to this expansion.
What was the impact of the new diamond sources on European diamond hubs?
European diamond hubs continued to thrive
The ample supply of diamonds supported the growth of these hubs.
Which city became a diamond manufacturing and trading hub in the late 19th century?
New York
This shift added to the complexity of the global diamond market.
When did the Indian diamond cutting industry begin to reawaken?
At the end of the 19th and beginning of the 20th centuries
This resurgence was significant for the global diamond industry.
Which merchants were instrumental in the reawakening of the Indian diamond cutting industry?
Merchants from Palanpur, Gujarat. They played a key role in connecting Indian diamond cutting with European markets.
Where did the merchants from Palanpur, Gujarat set up diamond buying offices?
In Antwerp and other European trading centers. This establishment facilitated the trade of diamonds between India and Europe
What industry did Belgian and Dutch Jews establish in Israel by the end of the 1930s?
Diamond cutting factories
Their expertise secured Israel as an essential player in the diamond industry.
How did European diamond cutting hubs like Antwerp and Amsterdam fare after World War II?
They never fully recovered
The impact of World War II hindered their diamond industry.
What significant policy change occurred in India in 1962 regarding diamonds?
India lifted diamond import restrictions
The condition was that finished stones would be exported to generate profit.
What milestone did India achieve in 1964 in the diamond industry?
The first Indian manufacturer became a sightholder
This marked India’s growing influence in the diamond trade.
As of 2015, how many Indian manufacturers were sightholders?
70 Indian manufacturers
This surpassed the numbers from every other country.
When did China enter the diamond cutting industry?
In the mid-1990s
China focused on branded cuts and high-quality cuts.
How does China’s diamond cutting scale and infrastructure compare to India’s?
China’s scale and infrastructure still can’t compete with India’s
Despite being a newer player, India’s established position remains stronger.
What were the three significant advancements in diamond cutting technology in the 20th century?
Rough mapping, computerized planning, and laser processing
Which countries played critical roles in developing diamond cutting technologies in the early 1980s?
Israeli and Indian companies
What impact did advancements in diamond cutting technology have on the industry?
Made diamond cutting more efficient and more profitable
What benefits did the advancements in diamond cutting technology provide?
Allowed for more complicated designs and greater precision
True or False: Historically, finished diamonds were cut more complexly than modern cuts.
False
What do experts rely on to understand the appearance of early diamond cuts?
Images and descriptions of jewelry in old paintings, catalogs, and diaries
Fill in the blank: The diamond cutting industry is driven by improvements in tools and technology, but consumers primarily covet _______.
[beautifully cut diamonds]
What is the relationship between the complexity of diamond cuts and consumer preferences?
Consumers prefer beautifully cut diamonds, which are often more complex than historical cuts
What is the earliest diamond cut known?
The point cut
In which century did the point cut appear?
Late 13th century
Until which century was the point cut common?
15th century
What shape did the point cut closely follow?
Rough’s octahedral shape
What did cutters do to the sides of the diamond in the point cut?
Polished off bumps and growth marks
How much did the point cut change the natural octahedron’s angle?
Only a few degrees
What made point cuts difficult to distinguish from natural octahedral rough?
Similarity in appearance to perfect octahedral crystals (glassies)
What did cutters find about the tips of stones in the mid- to late 1400s?
They tended to chip or break easily.
What technique did cutters begin to use on the tips of stones?
They began to grind the tip off so it was flat.
What is the result of grinding the tip off a stone?
A polished square facet known as the table cut.
What is the name of the smaller square facet created by removing the lower point of the crystal?
The culet.
How does the table cut appear when viewed from above?
It looks like a square within a square.
Why did the table cut appeal to Renaissance Europe?
It aligned with their interest in classical proportions.
What was an important quality of the table cut regarding light?
It increased the amount of light that returned to the observer’s eyes.
What effect did the table cut have on diamonds compared to point-cut stones?
It gave table-cut diamonds more brilliance and fire.
During which centuries did table cuts dominate diamond jewelry?
Through the 1500s and into the 1600s.
When did the rose cut appear?
Early 16th century
Until what century was the rose cut popular?
19th century
What is a characteristic feature of the rose cut?
Flat bottom and triangular facets that come to a point at the top
What effect do the facets of the rose cut produce?
Considerable brilliance that flickers near candlelight
What is the difference between the rose cut and the double rose?
The double rose has faceted peaks on both sides instead of a flat bottom
What does the briolette resemble?
An elongated double rose
Fill in the blank: The rose cut made efficient use of flat rough or chips created by _______.
[cleaving]
True or False: The rose cut was the only variation developed by cutters.
False
What were the base cuts for future brilliant cut designs?
Single cut and double cut
These cuts also increased brilliance.
In which century was much of the religious jewelry containing diamonds created?
Early 1600s
This period saw significant use of diamonds in jewelry.
What is the alternative name for the single cut introduced in the mid-1600s?
Eight cut
This style was based on the shape of octahedral rough.
How many facets does the single cut have?
17 facets
Includes a table, eight crown facets, eight pavilion facets, and sometimes a culet.
Who requested the design of the Mazarin cut?
Cardinal Jules Mazarin
This request led to the development of a new faceted diamond cut.
How many facets does the Mazarin cut have?
34 facets
The Mazarin cut is also known as the double cut.
What did the single cut serve as the basis for?
Full-cut modern brilliant
This evolution marked a significant advancement in diamond cutting.
What technological advancements influenced the creation of more facets in diamond cutting?
Technological breakthroughs in the previous century
These advancements occurred in the mid-1600s.
What evolved from the experimentation with more facets in the mid-1600s?
Modern brilliant cut
This development marked a significant step in diamond cutting techniques.
What compensated for shrinking diamond production from India in the mid-1700s?
Diamond rough from Brazil
This influx allowed for more cutting experiments to be conducted.
What are the two notable early diamond cuts mentioned?
Old mine cut and old European cut
These cuts are considered some of the best examples of early brilliants.
Describe the old mine cut.
Cushion shape with a high crown, deep pavilion, and large culet, it has 58 facets
It has 58 facets like the modern brilliant but offers less brilliance and fire due to its deeper pavilion.
Which diamond cut was the most popular in the 18th century?
Old mine cut
This cut was favored during that time period.
What distinguishes the old European cut from the old mine cut?
It has a circular girdle
This cut is the predecessor of the modern round brilliant cut.
Why did early brilliant cuts often have a cushion shape?
Before the invention of the bruting machine in the 19th century the square outline was easier to shape and followed the outline of the octahedral crystal closely
What was the next most common outline shape after the cushion shape for diamond cuts?
Circular
Other shapes like oval, pear, and marquise were cut but were less common.
Fill in the blank: The old mine cut has the same number of facets—_____—as the modern brilliant.
58
This similarity in facets is a key characteristic.
True or False: The old European cut is characterized by a square girdle.
False
The old European cut features a circular girdle.
What were other shapes of stones cut in the 18th century?
Oval, pear, and marquise. These shapes were less common during that time.
In which century were oval, pear, and marquise-shaped stones cut?
18th century
This period saw the introduction of these shapes in stone cutting.
True or False: Oval, pear, and marquise-shaped stones were very common in the 18th century.
False. These shapes were noted to be less common.
What is the feminine form of the French word ‘marquis’?
Marquise
What title does ‘marquis’ represent in royal rank?
A title of royal rank between a duke and an earl
What shape does ‘marquise’ describe in the gem and jewelry trade?
An elongated oval with pointed ends
How does the marquise shape compare to the natural outline of a diamond crystal?
It is quite different
How many years of improvements led to the introduction of the modern brilliant cut?
More than 500 years
In which era was the modern brilliant cut introduced?
In the early 1900s
What does the modern brilliant cut showcase in diamonds?
A diamond’s brilliance and fire with dazzling effectiveness
Which brilliant cut has dominated the market?
The round brilliant cut
What is notable about the round brilliant cut in the context of jewelry?
It has been the most influential
True or False: Cutters have only applied brilliant cuts to the round shape.
False
Fill in the blank: The marquise shape is an elongated oval with _______.
pointed ends
What is the primary purpose of the modern brilliant cut?
To showcase a diamond’s brilliance and fire
When can the development of the modern round brilliant be traced back to?
The late 1800s
This period marks significant advancements in diamond cutting techniques.
Who was Henry Morse?
A Boston diamond cutter and one of the inventors of the bruting machine
Morse’s innovations significantly impacted diamond cutting.
What was the purpose of the bruting machine invented by Henry Morse?
To make a diamond perfectly round
This machine was crucial in achieving optical efficiency in diamond cutting.
What method did Henry Morse use to improve diamond cutting?
Studied large numbers of faceted diamonds by measuring their facet angles
This empirical approach led to better cutting designs.
What did Morse discover after much trial and error?
A range of angles and proportions that produced the desired optical effect
This discovery was foundational for the modern round brilliant cut.
In what year did Henry Morse begin advertising his diamonds?
1870
This marked the beginning of the promotion of the modern round brilliant cut.
Who published round brilliant cut proportions in 1919?
Marcel Tolkowsky
Tolkowsky’s work built upon Morse’s findings.
How did Tolkowsky’s recommendations influence the diamond industry?
They influenced diamond manufacturers in America and Europe
This led to the widespread adoption of the modern round brilliant cut.
What was the impact of the modern round brilliant cut on the market?
It began to dominate the market
This reflects the cut’s popularity and effectiveness.
Fill in the blank: The bruting machine allowed cutters to make a diamond _______.
perfectly round
Name cut
Mazarin cut
Modern Briliant
Modern brilliant
Name Cut
Old European
Name cut
Old mine cut
Name cut
Point cut
Name cut
Single cut 8 cut
Name cut
Table cut
What was a priority in diamond cutting before 1900?
Weight retention
Weight retention was crucial to maximize the value of rough diamonds.
What innovation allowed for more efficient use of rough diamonds?
The diamond saw
The diamond saw enabled better cutting techniques that retained more weight.
How did the brilliant-cut diamonds change after 1900?
They were cut quite differently with new angles and proportions
This change aimed to enhance the diamond’s visual appeal.
What feature of diamond cutting became popular during the transition to the modern cut?
A very thin girdle edge
A thin girdle edge allowed for more light to enter the diamond, enhancing its brilliance.
What modifications were made to the modern round brilliant cut over time?
- Lengthening the lower girdle facets
- Increasing girdle thickness to avoid chipping
- Increasing the table size
These modifications were influenced by Tolkowsky’s standards.
By what year had the round brilliant cut reached its modern shape?
By 1950
This year marks the establishment of the round brilliant cut shape recognized today.
What term was promoted by manufacturers in the 1990s for round brilliants?
Ideal cut
The ideal cut was marketed as having the best proportions for brilliance and fire.
What did GIA’s research on cut evaluation suggest about diamond proportions?
Many different proportion combinations succeed equally well
This indicates that there is no single ‘ideal’ cut that guarantees beauty.
What ultimately matters in the perception of a diamond’s beauty?
The perceived beauty of a diamond. Individual preferences play a significant role in how diamonds are valued.
True or False: The modern round brilliant cut is no longer popular among consumers.
False
The modern round brilliant cut continues to be a favored choice for consumers.
What is the crown of a faceted gem?
Top part of a faceted gem, above the girdle.
What is the table facet?
Facet at the top of the crown; usually the largest facet on the stone.
What are upper half facets?
Facets that extend from the girdle edge toward the table.
What are bezel facets?
Kite- or diamond-shaped facets between the table and the girdle.
What are star facets?
Facets that extend from the table edge toward the girdle.
What is the girdle in a faceted gem?
Narrow section that forms the boundary between a stone’s crown and pavilion.
What are lower half facets?
Facets that extend from the girdle edge toward the culet.
What is the pavilion of a faceted gem?
Lower part of a faceted gem, below the girdle.
What are pavilion main facets?
Kite- or diamond-shaped facets between the girdle and the culet.
What is the culet?
Small facet at the bottom of the diamond, where the pavilion mains meet.
What is the purpose of the culet?
To protect loose diamonds against abrasion and chipping.
How many facets does a standard round brilliant have in total?
57 or 58
How many bezel facets are there in a standard round brilliant?
8
How many star facets are present in a standard round brilliant?
8
What is the number of upper half facets in a standard round brilliant?
16
How many pavilion main facets are there in a standard round brilliant?
8
What is the number of lower half facets in a standard round brilliant?
16
How many culet facets can be found in a standard round brilliant?
0 or 1
When did fancy-shape diamonds begin to be cut?
In the 16th century
What inspired cutters to apply the modern brilliant style to fancy shapes?
The success of the round brilliant
What was an important development in diamond cutting that made efficient use of flat rough?
The triangular brilliant
Who developed the triangular brilliant in the early 1960s?
Leon Finker
What name did Leon Finker give to the triangular brilliant he developed?
Trillion
What did people begin to refer to any triangular brilliant as?
A trillion
What was the impact of exploring new shapes in diamond cutting?
Made more efficient use of oddly shaped and off-color rough
What was the result of the efficient use of rough in diamond cutting?
Greater quantities of desirable and profitable finished stones
Fill in the blank: The triangular brilliant became so popular that people began referring to any triangular brilliant as a _______.
trillion
True or False: The triangular brilliant is the only variation of the cut that has different brand names.
False
What is the name of the rectangular brilliant-cut diamond patented by Henry Grossbard?
The radiant
Patented in the late 1970s.
What cut appeared soon after the radiant and emphasized brilliance?
The princess cut
It is a square or rectangular brilliant cut.
What is the purpose of the fancy brilliant cut?
To make the best of a diamond’s color
It changes proportions and angles to impact color appearance.
How can cutters impact the color appearance of a diamond?
By changing proportions and angles
This affects the light path to deepen or lighten color.
What advancements have made cutting fancy-shape brilliants easier?
Advances in technology and engineering
This has made these diamonds more affordable.
In the past 20 years, what has happened to the market for fancy-shape brilliants?
Greater quantities have made their way to the market
This indicates increased availability.
Fill in the blank: The _______ cut emphasizes brilliance and uses the rough even more efficiently.
princess
This cut is related to the radiant cut.
True or False: The fancy brilliant cut is designed to minimize the appearance of a diamond’s color.
False
It aims to enhance the color appearance.
What is one factor that influences diamond cut trends?
Changes in popularity of different shapes and cut styles
Trends in luxury goods, including diamonds, evolve over time.
Which diamond shape was the most common before 1880?
Cushion shape
The cushion cut was favored prior to the 1880s.
What diamond cut was highly desired in the 1970s and 1980s?
Marquise cut
The marquise cut gained popularity during this time period.
Which diamond cut has been the most popular since the late 19th century?
Modern round brilliant cut
This cut has maintained its popularity over the years.
True or False: Older diamond cuts never return to popularity.
False
Trends can cycle back, leading to older cuts reemerging in the market.
Fill in the blank: The _______ was the most common diamond shape before 1880.
Cushion shape
Fill in the blank: The _______ cut was highly desired in the 1970s and 1980s.
Marquise
List the three diamond cuts mentioned and their associated time periods.
- Cushion: before 1880
- Marquise: 1970s and 1980s
- Modern round brilliant: since late 19th century
What is one factor that influences diamond cut trends?
Changes in popularity of different shapes and cut styles
Trends in luxury goods, including diamonds, evolve over time.
Which diamond shape was the most common before 1880?
Cushion shape
The cushion cut was favored prior to the 1880s.
What diamond cut was highly desired in the 1970s and 1980s?
Marquise cut
The marquise cut gained popularity during this time period.
Which diamond cut has been the most popular since the late 19th century?
Modern round brilliant cut
This cut has maintained its popularity over the years.
True or False: Older diamond cuts never return to popularity.
False
Trends can cycle back, leading to older cuts reemerging in the market.
Fill in the blank: The _______ was the most common diamond shape before 1880.
Cushion shape
Fill in the blank: The _______ cut was highly desired in the 1970s and 1980s.
Marquise
List the three diamond cuts mentioned and their associated time periods.
- Cushion: before 1880
- Marquise: 1970s and 1980s
- Modern round brilliant: since late 19th century
What are the four main stages of diamond cutting?
Planning, rough dividing, outline or profile shaping, and polishing.
What factors influence the steps and sequence in diamond cutting?
The goal or results cutters want to achieve.
Fill in the blank: The first stage of diamond cutting is _______.
[planning]
Fill in the blank: The last stage of diamond cutting is _______.
[polishing]
True or False: The steps within each stage of diamond cutting are the same for all cutters.
False
What has allowed greater precision and efficiency in diamond cutting today?
Technological breakthroughs
These advancements have improved every stage of the cutting process.
What is the most crucial stage of diamond cutting?
Planning. The profitability of a diamond manufacturing business depends on effective planning.
What do planners study to develop a cutting plan for diamond rough?
Planners study the following features:
* Crystal directions
* Surface features
* Inclusions
Understanding these features helps in visualizing the crystal structure.
What tools did planners originally rely on to identify crystal directions?
Planners relied on clues such as:
* Growth marks
* Cleavage
These clues helped in determining how to divide the rough.
What challenges did planners face when inspecting inclusions in diamond rough?
Challenges included:
* Using loupes and microscopes
* Frosted surfaces blurring or blocking views
* Needing to polish ‘windows’ on the surface
These tasks required substantial knowledge and experience.
What is the goal of the planning stage in diamond cutting?
To develop a cutting plan based on the unique features of each piece of diamond rough. This involves combining results with market value analysis for decision making.
Fill in the blank: The planning process was originally _______.
manual
Initial planning relied heavily on manual inspection techniques.
What is the significance of crystal direction in diamond cutting?
It is extremely important for determining how to divide the rough. Correct identification of crystal direction affects the overall quality of the cut.
What is essential for planners and cutters of diamond crystals?
Knowledge of a diamond crystal’s structure
Understanding the structure helps in making informed cutting decisions.
What are the principal sawing directions of a diamond?
Cubic and dodecahedral planes
These planes are crucial for effective cutting.
What is the cleavage direction of a diamond?
Octahedral plane
The cleavage direction is important for understanding how the diamond may break.
What machines are widely used in modern diamond cutting factories?
Machines that facilitate planning
These machines help planners see both surfaces and internal features of rough diamonds.
What must planners balance to maximize profit?
Market value, weight retention, and quality
This balance is crucial for efficient use of rough diamonds.
What was developed around 2009 that revolutionized diamond planning?
New planning technology
This technology introduced rough mapping and computer-aided planning.
What are the two elements of the new planning technology?
Rough mapping and computer-aided planning
These elements help in making informed cutting decisions by studying the rough.
How does modern technology differ from previous methods in diamond cutting?
It focuses less on crystal orientation
Laser technology allows splitting without being constrained by crystal direction.
What is the first step of mapping diamond rough?
Submerge it in a solution with a metal frame or wrap it in glass
This process allows for scanning or mapping the diamond in three dimensions.
What does the imaging system do during the mapping process?
It scans or maps the diamond in three dimensions
This results in a detailed view of the stone’s internal features.
What additional mapping capability do some machines have?
Detailed surface mapping
Surface mapping reveals features that might influence cutting decisions.
How are the mapping results saved for analysis?
As videos or images
This allows for thorough analysis of the rough diamond.
What advantage does the new technology provide to inexperienced planners?
A clear view of the rough diamond
This enhances their ability to make informed cutting decisions.
What is the purpose of the software used with the scanning machine?
To analyze the scan and latest market value trends to propose multiple cutting plans
The software may also analyze inclusions based on their impact on the finished stone’s durability and clarity.
How do manufacturers enhance cutting plans?
By developing custom software based on market and client preferences
This customization allows for more tailored cutting solutions.
Who ultimately makes the final decision on cutting plans?
The operator
Despite the use of advanced technology, human control remains essential.
What role do planners play in modern diamond cutting factories?
They evaluate or adjust the computer-proposed cutting plans based on their observations and strain in the stone
This adjustment process is critical for optimal cutting outcomes.
Is strain evaluation automated in cut planning?
No, strain evaluation is still not automated
It remains a critical aspect of the cut planning process.
How do planners determine the strain in a stone?
By observing the stone using a polariscope and often magnification
This method allows for a detailed analysis of the stone’s characteristics.
Fill in the blank: The software analyzes inclusions based on their impact on the finished stone’s _______.
[durability and clarity]
What is the primary goal of planners at different levels?
Achieving the most profit
Planners focus on maximizing profitability through their plans.
What often involves debate in the planning process?
Developing a cutting plan
This debate is crucial for arriving at the most effective strategies.
What do manufacturers often implement to encourage discussion among planners?
Reward systems
These systems reward planners for creating the most profitable plans.
How is the cutting plan finalized for production?
Lines are marked on the rough by hand or with a marking device linked to software
This step prepares the material for the subsequent steps in the cutting process.
What tool do planners use to mark small stones?
A microscope
This precision tool allows for accurate marking of small details.
Which countries are at the forefront of diamond cutting technology?
Israel and India
What is dominating the diamond manufacturing business?
Online diamond trading
What has improved dramatically in the last decade regarding diamond cutting?
Surface and inclusion mapping capabilities
What does continuous refinement of computer software and mapping technology provide to planners?
More information
What gemological tool is used by planners to check strain?
Polariscope
What is required to accurately locate strain and recognize its severity?
Many years of experience
What will new technology enable in relation to strain mapping?
More precise strain mapping
True or False: Online diamond trading allows for more accurate cutting plans.
True
Fill in the blank: Continuous refinement of computer software and mapping technology delivers more _______ to planners.
information
What is the goal of the stage before cutting marked rough diamonds?
To precisely execute the plan with minimal waste
This stage focuses on maximizing the efficiency of the cutting process.
In which century did cutters first understand that diamond crystals could be split along their cleavage planes?
The early 1400s
This knowledge was critical for the development of diamond cutting techniques.
What is the term for the notch that cutters create to prepare for cleaving a diamond?
Kerf
The kerf is essential for positioning the cleaving blade accurately.
What tool do cutters place in the kerf before cleaving a diamond?
A steel cleaving blade
This blade is tapped with a hammer to split the diamond.
What is the consequence of making a mistake during the cleaving process?
It could destroy a diamond
Precision and concentration are crucial in the cleaving operation.
Is cleaving a common technique in modern diamond cutting?
No, cleaving is rare today
Modern splitting techniques have largely replaced traditional cleaving methods.
Fill in the blank: Cutters used a sharp piece of diamond to scrape a notch called a _______ into the marked rough.
kerf
The kerf is a critical step in the cleaving process.
What happens after the steel cleaving blade is placed in the kerf?
The blade is tapped with a hammer
This action is what splits the diamond cleanly in two.
Describe the skill required for the cleaving operation.
Much skill and concentration
The operation is delicate, and precision is necessary to avoid damaging the diamond.
What did the use of sawing expand in diamond processing?
The ways a diamond could be divided
Is sawing easier in cleavage directions?
Yes
What was a significant benefit of early sawing techniques?
More efficient use of the rough and increased weight retention
What technology dramatically increased the efficiency of diamond sawing?
The rotary saw
What technology has largely replaced the rotary saw in diamond processing?
Laser sawing
When are rotary saws still used in diamond processing?
For strained stones, which can be damaged by laser sawing
How does a laser beam cut diamonds?
With heat
What advantage does laser sawing have over blade sawing?
It follows planning marks on the rough more precisely
How is the precision of laser sawing controlled?
By computer software
Fill in the blank: A laser can split the rough along any _______.
Direction
What is one advantage of laser sawing compared to blade sawing?
Laser sawing retains more weight than blade sawing.
What is a drawback of laser sawing?
It can damage some rough diamonds, especially those with a lot of strain.
What is the most widely used laser in the diamond industry?
Solid state neodymium-doped yttrium aluminum garnet laser (Nd: YAG).
What is the most common energy level for Nd: YAG lasers?
532 nm level or green laser.
What shape does a conventional laser beam leave on a diamond?
Cone-shaped cut.
What technology was developed for better weight retention and less damage in laser sawing?
Laser guided by a water jet.
What principle does the advanced laser sawing system utilize to keep the beam in focus?
Principle of total internal reflection.
What is the maximum working range of the advanced laser sawing system?
Up to 50 mm.
How long does it take to cut a 10-ct. diamond using the advanced laser sawing system?
About 30 minutes.
What is the role of water in the advanced laser sawing system?
It acts as a cooling agent to reduce potential damage.
What feature allows operators to program laser cutting machines?
Computerization.
How many rough stones can be cut in one run with the latest laser cutting technology?
Up to two dozen.
What are the names of the cutting shapes enabled by the latest laser technology?
Pie sawing or scoop sawing.
Fill in the blank: The advanced laser sawing system requires little _______.
focusing.
What follows sawing in the diamond cutting process?
Bruting
Bruting shapes the diamond rough to the projected profile of the finished stone.
What is the goal for round stones during bruting?
A perfectly round girdle
For fancy shapes, achieving a smooth and symmetrical profile is more challenging.
What begins to happen to the rough diamond during bruting?
It begins to look more like a finished gem
How are rough diamonds typically bruted?
By forcing one diamond against another to shape a rounded girdle
What is a dop?
A holder that secures a diamond during processing
What does the operator do with the dop during bruting?
Fastens the rough diamond onto a rotating lathe and presses the bruting diamond against the spinning rough
What happens to the diamond used for bruting?
It begins to take on a round outline as well
What was a drawback of traditional bruting?
It was a trial-and-error process requiring frequent interruptions
Why is centering important during bruting?
Diamonds bruted off-center can lose a significant amount of weight
What significant change occurred in the late 1980s regarding bruting?
Bruting was fully automated
How many stones can be bruted simultaneously with automation?
Two stones
What advantage does automated bruting have over traditional methods?
It requires little supervision and allows one skilled cutter to monitor several machines
What issue has automated bruting virtually eliminated?
Bearding, or minute fractures running perpendicular to a bruted girdle
What is the result of automated bruting in terms of diamond shape?
More consistent roundness
What is more difficult compared to bruting round-shape diamonds?
Fancy-shape bruting
Fancy-shape diamonds require more precision in the bruting process.
When was laser bruting introduced?
1992
This marked a significant advancement in diamond cutting technology.
What advantage does laser bruting have over traditional bruting?
Creates precise and symmetrical outlines more easily
Laser technology allows for greater accuracy in shaping diamonds.
Which shapes has laser bruting been especially helpful for?
Fancy and asymmetrical outlines
These shapes are more complex and require advanced techniques.
What can the cutter do with the laser bruting device?
Program it to work with minimal supervision
This automation increases efficiency in diamond cutting factories.
What do many diamond cutting factories primarily use to brute fancy-shape diamonds?
Lasers
Lasers have become the standard for cutting more intricate diamond shapes.
How are round-shape diamonds primarily bruted?
By automated machines
This method remains effective for simpler diamond shapes.
What is coning in diamond cutting?
Coning is the process of forming the pavilion angle of a diamond, resulting in a cone-like shape of the pavilion
Coning often follows bruting and is most commonly performed on round-shaped stones.
How is the coning process performed?
The diamond is dopped and placed horizontally to spin against a vertical shaping wheel with consistent pressure and cooling liquid
This method limits contact with the wheel and reduces risk for highly strained stones.
What is a scaife in diamond cutting?
A scaife is a rapidly spinning horizontal wheel coated with diamond powder used to polish diamond rough
The longer a diamond is polished on a scaife, the higher the risk of damage, especially for strained stones.
What factors do manufacturers evaluate when planning for coning?
Manufacturers evaluate strain in the stone to determine whether it can undergo standard coning or be put on the scaife
This evaluation is crucial to prevent damage to the stone.
Can laser technology be used in coning?
Yes, laser technology can be applied to coning, but it is not common
Automated laser machines, known as 4P, can perform multiple processes including sawing, cutting the table, bruting the girdle, and coning.
What does the term ‘4P’ refer to in diamond cutting?
‘4P’ refers to automated laser machines that perform four processes: sawing, cutting the table, bruting the girdle, and coning the pavilion and crown angles
The software in these machines can reposition the diamond for multiple steps.
Fill in the blank: Coning is most commonly done on _______ stones.
round-shape
True or False: Coning is a manual process in diamond cutting.
False
What is the last phase of the cutting process for diamonds?
Polishing
Polishing gives a diamond its finished dimensions.
What two processes occur simultaneously during the final cutting phase of diamonds?
Faceting and polishing
People in the trade use these terms interchangeably.
What is a scaife in diamond polishing?
A device typically made of cast iron and coated with diamond powder
Used to polish the rough diamond.
How were scaives originally powered?
By hand levers
They spun a drive wheel connected to the scaife’s shaft.
What powered scaives after hand levers?
Horses, then steam, and ultimately electric motors
This shows the evolution of technology in diamond polishing.
What device holds the diamond in place during polishing?
Tang
The tang allows for adjustment of the diamond’s angle.
What is the significance of maintaining the diamond’s angle during polishing?
It must be polished perpendicular to its graining
Polishing parallel to the graining is incorrect.
Fill in the blank: The tang rests on a steady surface near the _______.
scaife
True or False: Polishing and faceting are two distinct processes in diamond cutting.
False
They occur simultaneously and are often used interchangeably.
What is blocking in the context of diamond polishing?
A crucial step in polishing where the cutter polishes the first 17 or 18 facets.
Which facets are polished during the blocking step?
The table, culet, eight crown main facets, and eight pavilion main facets.
What is the state of the diamond after the blocking process?
The diamond is a single cut.
When does the blocking process stop for some small stones?
It stops after polishing the first 17 or 18 facets.
Why must blocking be done carefully?
It establishes the diamond’s basic symmetry.
What happens if the blocked diamond is uneven?
It must be blocked again, resulting in weight loss.
How does the cutter block the entire diamond?
By turning it several times and polishing facets in a specific order.
What technique do skilled cutters use to fashion diamonds accurately?
They line up facet reflections and the corners of intersecting facets by eye.
True or False: The crown and pavilion facets must be aligned at the girdle.
True.
Fill in the blank: During blocking, the cutter usually polishes a facet and then _______.
repositions the stone and polishes another facet directly opposite the first one.
What is the last step in the cutting process called?
Brillianteering
This step involves polishing the remaining facets of the stone.
What facets are typically polished during standard brilliant cuts?
Star and upper and lower half facets
These facets are essential for achieving the desired brilliance in the cut.
In high-quality stones, what additional part may be polished by the cutter?
The girdle
Polishing the girdle is common for fine-quality stones to enhance their overall appearance.
How many automated polishing machines can one operator supervise in modern factories?
Multiple machines
Automation allows for increased efficiency in the polishing process.
Is a human touch still needed after automated polishing?
Yes
The human touch is necessary to ensure quality after the initial automated process.
Which stage of the cutting process is the most manual labor-intensive?
Polishing
This stage requires significant manual effort compared to other stages in the cutting process.
What is laser sawing?
Routine process in diamond cutting using laser technology
Laser sawing is part of modern diamond cutting techniques.
What processes can be accomplished with lasers in diamond cutting?
Bruting, coning, faceting, and blocking
These processes were traditionally done by hand.
What is the 4P laser machine used for?
Sawing, bruting, coning, and faceting the table
The 4P machine represents a significant advancement in diamond cutting technology.
What additional capability does the 5P laser machine have compared to the 4P machine?
Can block the stone
The 5P machine performs all functions of the 4P machine and adds blocking.
What is the role of a cutter in modern diamond cutting?
Skilled touch needed to achieve ideal appearance
Despite advancements in technology, human skill remains vital in the finishing process.
Fill in the blank: Laser _______ is a process that replaces traditional hand techniques in diamond cutting.
sawing
True or False: All diamond cutting processes are now fully automated with lasers.
False
While laser technology has advanced, human skill is still required for optimal outcomes.
What are the four processes referred to as 4P in diamond cutting?
Sawing, bruting, coning, and faceting
These processes are essential in shaping diamonds.
What is the significance of technological breakthroughs in modern diamond cutting?
Combination of technology and human skills enhances diamond cutting precision
The evolution of technology has transformed the diamond cutting industry.
What do manufacturers need to meet according to modern consumers?
Standards of modern consumers more educated about diamonds than in years past
Why has quality control become important in the diamond cutting process?
Manufacturers must meet the standards of modern consumers
What is an important step in the diamond cutting process?
Quality control
What teams do all factories have that evaluate finished diamonds?
Quality control teams
What are the experienced teams in factories evaluating diamonds based on?
The 4Cs
How is the cut quality of diamonds assessed?
The cut quality is assessed and graded as it would be in a grading laboratory.
What role do quality control specialists play in diamond manufacturing?
Quality control specialists determine whether the stones match the standards requested by specific buyers.
What have some factories developed to assist with quality control?
Some factories have developed machines to automate part of the quality control process.
What happens to stones that meet quality standards?
Stones that meet the standards are moved to the next step for packing and trading.
What occurs with stones that do not meet the quality standards?
Stones that do not meet the standards return to an earlier stage for modification and refinement.
What must manufacturers do to keep up with the diamond cutting industry?
Manufacturers must continue investing in new technology.
What benefits do new technologies provide in diamond manufacturing?
New technologies help automate the cutting process and improve precision, efficiency, and weight retention.
What initial approach characterized the diamond manufacturing industry?
The diamond manufacturing industry began with a human touch.
How do modern diamond cutters enhance their work?
Cutters can combine their intuition, experience, and skill with the latest technology.
Why are fashioned diamonds appealing to buyers today?
Fashioned diamonds are appealing because they meet modern quality standards.
