On Wed, 05 Jan 2005 00:25:18 -0800, in ?? vj wrote:


]Neither treatment is generally used with either stone. Both generally are used just as
]dug up.

**smile**
the jeweler i'm apprenticing with commented that "unless you dug the
stone out of the ground yourself, or know who did, odds are it has
been treated *somehow* before it got to you. these days, it's very,
very difficult to find stones that have not been treated, especially
if you're buying them for jewelry. one more reason i'm not really
interested in being that kind of jeweler, and for belonging to my
local rock club!

While your statement is certainly true in general with stones these days, as it happens,
peridot in particular, and moonstone also in most cases, happen to be stones for which
useful treatments do not yet exist, at least in terms of the treatments such as heat
treatment or irradiation for color improvement. Thus those two generally can be
trusted to be untreated. One must, of course, still make sure that your peridot is
indeed peridot rather than some imitation or other similar stone. As a general rule,
the feldspars as well, (moonstones) are not improved by this type of treating, though
some porous types can be dyed, and one might find things like a surface laquor or wax
used with or even instead of a conventional polish on the surface. And both perodot or
moonstone, if found with fractures and flaws, might be oiled ot otherwise resin treated
to help hide those fractures. With peridot, however, this is still unlikely, since the
stuff even without fractures is fragile, and oiling or fracture filling does not
increase the strength of a stone, so peridot with enough fractures to benefit from
fillings, probably wouldn't survive long enough to make it through cutting, or to
market. This is only likely an issue with low quality cabochon cut peridots, not
facetted ones, and even then, it's a marginal treatment at best. Not at all common.

So by the time we're done with that, in general, you can probably trust your peridot and
moonstones to not be treated in any really signficant way. If there's a little wax to
help the shine on the moonstones, who cares. Only the really cheap porous ones need
that, and they don't look like anything much more costly when it's done. . If that
moonstone happens to be dyed, then that means it's one of those translucent brown or
orange (etc) things. Dyed, maybe, but who cares. It's still only woth pennies per
carat, so it's not that important an issue, and the dyed ones look dyed, not like
something more valuable. The costlier good looking colorless/clear ones with nice blue
or white moonstone flash...-- those aren't treated.

Peter Rowe
(G.G. , 1979)