Demantoid is the proper spelling for one of the green garnets
you are interested in. Most of these newer mined stones are a
lighter green color, though with some brilliant tones. These
stones are expensive in the larger sizes due to their rarity.
Tsavorite, another green garnet, is available in richer, more
highly saturated shades of green. Stones that are above 2.5
carats in size are rare, however, I’ve seen stones that are 8
carats and larger. Campbell Bridges, the discoverer of
tsavorite, operates the largest producing mine in the world.
Contrary to some other I’ve seen posted on this
site, production was only slowed due to the rains during spring,
but mining has resumed and Bridge’s exploration company is
yielding some very fine material. The colors range from a light
pastel green, grass green, forest green, to a very deep saturated
dark green. Most of the stones are eye clean, unlike much
demantoid and unavoidably similar green colored emerald.
Tsavorite sets itself apart from many gems in that its color is
100% natural. It isn’t heat treated, filled, irradiated, dyed,
or enhanced in any manner. Mr. Bridges’ company Tsavorite USA is
listed in most trade publications such as the 1998 JCK Directory
and AGTA Directory. The quality of their material, cut,
reasonable prices, and extensive selection makes them the best
choice if you are looking for some fine stones.
Most people who compare tsavorite with demantoid garnet, prefer
the richer color of tsavorite. For those of you who’ve seen it
you know what I mean. Tsavorite will be seen in much more jewelry
in the future since mining production has increased significantly
and there is a readily available supply. If it had been
discovered before emerald, tsavorite would have been one of the
"precious gems". It is the best alternative to emerald since it
isn’t heavily included, has a hardness of approximately 7.5, is
highly durable, and has a high refractive index which gives it a
high luster. Once the general public becomes more aware of this
gem, it will likely be simialar to tanzanite in its popularity.
Good luck! If you contact Tsavorite USA, pLease say Duncan
recommended you contact them.