Assignment 8 - Diamond Cutting Flashcards
When did diamonds first appear in Jewelery?
100 AD, diamonds were set into jewellery by the Romans. Around 1200 AD they began to appear in royal European jewellery.
How did improvements of tools advance diamond cutting?
Before the 15th century, diamond “cutting” was limited to superficial polishing of the rough.
In the 16th century, developments of continuous rotary motion and the cast-iron polishing wheel shifted diamond cutting from superficial polishing to genuine faceting.
The process of dividing rough diamond along its cleavage planes
Cleaving
The process by which a rough diamond is shaped into its basic face-up outline to prepare for faceting
Bruting
The process of dividing a rough diamond into different sections using a saw.
Sawing
What are some important events in the history of diamond cutting?
- Invention of the bruting machine and the motorized diamond saw made mass production possible
- Rough mapping, computerized planning, and laser processing made diamond cutting more efficient and more profitable.
When and where did the first cut diamonds appear?
The first polished diamonds appeared in Europe around 1380.
A diamond cut with a flat bottom and triangular facets that come to a point at the top
Rose cut
What were the earliest diamond cuts?
- Point Cut (1300-1500)
- Table Cut (1400-1600)
- Rose Cut (1500-1800)
The cuts followed the shape of the octahedral rough.
How did the brilliant cut develop?
- Single Cut (1650)
- Old-Mine Cut (1700)
- Old European Cut (1750)
- Modern Brilliant Cut (1900)
What are some of the newer diamond cuts?
- Round Brilliant
- Princess Cut (Rectangular/Square)
- Triangular Brilliant
- Marquise Cut
- Pear Cut
A simple diamond cut, with a table, eight crown facets and sometimes a culet.
Single Cut
An early cushion-shaped brilliant with a high crown, deep pavilion, and 58 facets including a large culet.
Old-mine Cut
An early brilliant cut with a circular girdle.
Old European Cut.
What is a cutter’s main challenge?
The cutter’s challenge is to produce the most attractive and most profitable gem at the lowest production costs.
Why is the planning stage so crucial?
Planning has a massive impact on the profitability of the finished stones.
What are the main steps in the cutting process?
- Planning
- Cleaving / Sawing
- Bruting (& Coning)
- Polishing (Blocking & Brillianteering)
Dividing a diamond into two or more pieces along a cleavage plane
Cleaving
Dividing diamond rough into sections, either mechanically or by laser
Sawing
The person who decides where to mark diamond rough for fashioning into the most profitable polished gem
Planner
A notch scratched into a diamond rough to prepare it for cleaving
Kerf
A holder that secures a diamond during sawing, bruting, or polishing
Dop
Forming the basic face-up outline of a round or rounded-shape diamond to prepare it for faceting
Bruting
Placing and finishing facets on a rough diamond
Polishing
The process of forming the pavilion angle by gradually polishing off the extra material at different angles.
Coning
A rapidly spinning horizontal disc coated with diamond powder, used to polish diamond rough
Scaife
A device that holds the dop and allows polishers to adjust and maintain a diamond’s angle during polishing
Tang
Placing the first 17 to 18 facets on a diamond
Blocking
Placement and polishing of the star and upper and lower half facets
Brillianteering
What cut style results from blocking?
Single Cut
Why did cutters first make a table cut?
To avoid chipping
What outline shape was most common to early brilliant cuts?
Before the invention of the bruting machine, the cushion shape was the easiest to cut, because it follows the natural outline of octahedral diamond crystals.
Why did cutters apply the modern brilliant cut to fancy shapes?
To maximize profits from oddly shaped or off-color rough.
How does laser sawing increase weight retention?
Because the beam is thinner than with traditional saws.
What early cut introduced the culet?
Table cut.
