|
|
|
|
Gem
Cutting
Faceting involves the same sequence of grinding and
polishing steps used to make cabochons. In faceting,
the initial step is to cut a preform, a of gem material
roughly the size and shape of the finished gem vet containing
facets. The preform is clopped, and the dope stick a
in a special device called a faceting head.
. |
|
The
faceting head is a modern convenience component that
allows a stone to be precisely rotated and tilted to
desired angles. Proper angles are disered to bring out
the maximum brilliancy from a given gem. In Or Darts
of the world faceting heads are not used. |
| |
|
Instead,
a special employed, a vertical shaft less than a foot high
in which are ed holes penetrating at various angles and positions.
This pole, the peg, provides the "angular settings"
for cutting various gems. The inserts the dope stick into
one of these holes and rests the other end, which the gem
is attached, against a grinding wheel. Although the technique
sounds primitive, in the hands of an expert it can produce
able results.
|
|
 |
 |
|
DIAMONDS,
GEMSTONES & CRYSTALS
FACTS & FIGURES |
| Gem
Cutting
Each
facet is ground on the preform, the cutter stopping
the grinding r• when his eye tells him that the
facet has reached its correct size. are ground
by the action of abrasives against a flat, horizontally
running disc called a lap. The process is called
lapping.
Each
facet is individually ground, including the large
facet on top called the table. A gem is polished
in the same way as a cabochon, with each facet
undergoing successive fine-grinding stages and
terminating with a polishing agent. Today various
grit sizes of diamond are becoming increasingly
popular among lapidaries. Diamond tremendously
in ¬cutting speed, and produces a better polish.
. 
Facets
must be applied to both the top and bottom of
a faceted gem. the gem must be held on a clop
stick for cutting, only half the work be completed
at a time. When all the facets on one end are
rely polished, the dope stick is placed in a special
alignment jig. A second dop stick is attached
to the polished end while the stone is still attached
to the first stick. Then the original dope is
carefully removed and Otter dope stick inserted
in the faceting head or jamb peg. |
|
|
 |
| The
other wit the stone is completed in the same way as the first,
making sure !!.*r we new facets are exactly lined up with the
completed ones. |
 |
 |
 |
| diamond
1 | 2
| 3 |
|
|
|
