PERIDOT
Peridot
has enjoyed a recent rise in popularity. Fortunately, this increase
in demand has been offset by increased production, especially
from the fertile mesa of the San Carlos Apache reservation.
Peridot
is a clean stone, the darker the green the better the stone. Some
peridot can be very light and almost lime green, and thus is not
highly regarded. And while peridot most always has an olive tone
-- it's the gem variety of the mineral olivine -- look for stones
that aren't overwhelmingly olivey. And as with all faceted gemstones,
the cut should produce an even fire -- no large dark patches when
you look directly down on the table. You should also ask to observe
the stone in both incandescent and fluorescent lighting to get
an idea of how the color and fire will change when you wear your
jewelry under those lighting sources. Don't expect to find much
large material from Arizona, most of the San Carlos production
is under 3 carats. Chinese material is large but the color is
usually inferior to specimens from Pakistan -- which currently
produces the finest large quantities of peridot. Burma still produces
incredibly stunning, large (30 carats and up) stones, but these
are mainly collector's items as production is unreliable and accessible
to a handful of connected gem traders.
Peridot
is occasionally treated with colorless oil, wax, natural and synthetic
unhardened resins into voids to improve appearance. Surface fractures
are sometimes filled with a colorless hardened substance. These
treatments should be stable if done properly.
