older is rested in one of a
series of holes in what is called a "_ginpeg_" resting in the work-bench
near a metal lap, and the stone is pressed upon the rapidly rotating
surface of the lap, which is charged with diamond dust or carborundum,
according to the hardness of the material to be facetted. A flat facet
is thus ground upon the stone. By rotating the holder a series of
facets, all in the same set, is produced. The holder is then changed to
a new position on the ginpeg and another set of facets laid upon the
stone. Thus as many as four or five tiers or sets of facets may be
applied to one side, say the top of the stone. The latter is then
removed from the holder and cemented to it again, this time with the
bottom exposed, and several sets of facets applied.

The stone is now _cut_ but not _polished_. The facets are flat, but have
a rough ground-glass like surface. The polishing is usually done by
workers who do not cut stones, but who do nothing but polish them. In
small shops, however, the same lapidary performs all the parts of the
work.

POLISHING. The polishing of stones, whether cabochon or facetted, is
accomplished by the use of very finely powdered abrasives such as
corundum powder, tripoli, pumice, putty powder, etc. Each gem material
requires special treatment to obtain the best results. It is here that
most of the trade secrets apply.

The troubles of the lapidary in getting the keen polish that is so much
admired on fine gems are many. In general, the polishing powder should
not be quite as hard as the material to be polished, else it may grind
rather than polish. The material should be used with water or oil to
give it a creamy consistency. It should be backed by laps of different
materials for different purposes. Thus, when backed by a fairly hard
metal even tripoli, although much softer, will polish sapphire. On a lap
of wood, tripoli would fail to polish hard materials, but would polish
amethyst or other quartz gem. A change of speed of the lap, too, changes
the effect of the polishing material. I have seen a lapidary, who was
having no success at polishing an emerald, get very good results by
using a stick as a brake and slowing down his lap.

The polishing material must be of very uniform size, preferably water
floated or oil floated, to give good results. The lap must be kept flat
and true and the stone must be properly held, or the flatness of the
facets, upon which brilliancy depends in part