The Evolution of Diamond Cutting (Chapter 9, Key Terms, Key Concepts, & Diamond Manufacturing Terms) Flashcards
Placing the first 17 or
18 facets on a diamond.
Blocking
Placement and
polishing of the star and upper
and lower half facets
Brillianteering
Forming the basic face-up
outline of a round or rounded-shape
diamond to prepare it for faceting.
Bruting
Dividing a diamond
into two or more pieces along a
cleavage plane
Cleaving
A holder that secures a
diamond during sawing, bruting,
or polishing.
Dop
A notch scratched into
diamond rough to prepare it for
cleaving.
Kerf
An early
brilliant cut with a circular girdle.
Old European cut
An early cushion shaped brilliant with a high crown,
deep pavilion, and 58 facets
including a large culet.
Old-mine cut
The person who decides
where to mark diamond rough for
fashioning into the most profitable
polished gem.
Planner
Placing and finishing
facets on a rough diamond. Also
called faceting
Polishing
Dividing diamond rough
into sections, either mechanically
or by laser.
Sawing
A rapidly spinning horizontal disc coated with diamond
powder, used to polish diamond
rough.
Scaife
A simple diamond cut,
with a table, eight crown facets,
eight pavilion facets, and sometimes a culet.
Single cut
A device that holds the dop
and allows polishers to adjust and
maintain a diamond’s angle during
polishing
Tang
A rough diamond’s shape and crystal
structure influence the number, size,
and value of the finished gems it
yields.
Key Concept
The first polished diamonds appeared
in Europe around 1380.
Key Concept
The point cut and other early diamond
cuts followed the shape of octahedral
rough.
Key Concept
Early cutters used boards treated with
diamond dust and olive oil to shape
diamond rough.
Key Concept
The single cut was the basis for the
full-cut modern brilliant
Key Concept
The round brilliant is the dominant
diamond cut in today’s market.
Key Concept
Cutters apply the brilliant cut to fancy
shapes to get maximum profit from
oddly shaped or low-color rough.
Key Concept
The cutter’s challenge is to produce
the most attractive and most profitable
finished gem at the lowest production
cost.
Key Concept
Growth marks on the rough’s surface
help determine its internal crystal
directions.
Key Concept
Computer technology reduces some of
the diamond planner’s risk.
Key Concept
The rotary saw gave cutters the ability
to manufacture more than one fashioned
stone from a piece of octahedral rough.
Key Concept
Laser sawing allows more cutting
options than mechanical sawing.
Key Concept
Blocking is a crucial stage because it
establishes the gem’s basic symmetry.
Key Concept
High-tech diamond manufacturing
can increase efficiency and result
in consistently symmetrical finished
diamonds.
Key Concept
Frosted rough diamond. “Bark” in
Dutch.
Bast (Diamond Manufacturing Terms)
A person who cleaves, or splits,
a diamond along a cleavage plane. The
cleaver might also be responsible for planning the fashioning of a polished gem.
Cleaver (Diamond Manufacturing Terms)
A person who performs
the cross-working operations during
diamond polishing; sometimes called a
cross cutter
Cross worker (Diamond Manufacturing Terms)
Placing the bezel and
pavilion facets on round and fancy shapes.
Sometimes combined with blocking, especially on smaller stones. Also called cross
cutting
Cross working (Diamond Manufacturing Terms)
Irregular furrow or groove in the
surface of a diamond, characteristic of
diamond crystals in the gray color range.
Foss (Diamond Manufacturing Terms)
A diamond with
the table parallel to a possible cubic face.
Four-point diamond (Diamond Manufacturing Terms)
Dutch term for a feather in a
diamond.
Gletz (Diamond Manufacturing Terms)
Dutch term for a diamond that
has been cleaved, split, or sawn, but
not fashioned.
Kaps (Diamond Manufacturing Terms)
The natural, unpolished surface of
a rough diamond.
Naif (Diamond Manufacturing Terms)
A seventeenth-century term for
a diamond octahedron or other crystal shape
on which the natural faces are apparent.
Point naif (Diamond Manufacturing Terms)
A small diamond with a sharp
edge, cemented into a dop and used to
kerf another diamond in preparation for
cleaving. Or, a small diamond used to
brute diamonds or round up a girdle in
the final stages of polishing.
Sharp (Diamond Manufacturing Terms)
A person who splits a rough
diamond along a cleavage plane after it
has been kerfed by a laser. Not to be
confused with a cleaver, who is a master
craftsman
Splitter (Diamond Manufacturing Terms)
A diamond with
its table nearly parallel to a possible octahedral face.
Three-point diamond (Diamond Manufacturing Terms)
A diamond with grain
layers that are not on parallel planes, or
one with partial twinning
Twisted stone (Diamond Manufacturing Terms)
A blocking technique in which
the diamond is turned to position the
softest polishing direction against the
polishing wheel
Twisting (Diamond Manufacturing Terms)
A diamond on
which the table has been polished parallel
to a dodecahedral plane
Two-point diamond (Diamond Manufacturing Terms)
A historic term once used in
Europe to describe either the color or the
transparency of a diamond.
Water (Diamond Manufacturing Terms)
An early brilliant that has a circular girdle outline is called
old-European cut.
The number of facets on a single-cut diamond is
17 or 18 facets.
The cast-iron disc on which a diamond is polished is called a
scaife.
The person who decides where to mark diamond rough for fashioning is called the
planner.
The devices that grip and hold a diamond for polishing are known as the
dop and tang.
A diamond cutter’s main objectives are to produce an attractive finished diamond and
maximize profits.
In the cutting sequence, the crown and pavilion mains are polished by the
blocker.
The rotary saw contributed to the diamond cutting industry by
allowing for greater weight retention from rough.
The cutting style with a flat bottom and a variable number of facets that come to a peak at the top is the
rose cut.
The size of a finished gem depends greatly upon the rough diamond’s
shape.
The directional properties and structural features of a diamond crystal do not really matter in
laser sawing.
The process of polishing the star and upper and lower half facets is called
brillianteering.
When the rough has a frosty or non-transparent surface, the cutter can look for inclusions by
polishing a window to view the interior.
To help determine crystal directions, diamond cutters look for
growth marks.
A notch scratched into diamond rough to prepare it for cleaving is called a
kerf.