vj found this in rec.crafts.jewelry, from "Peter W.. Rowe,"
:

]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!


--
@vicki [SnuggleWench]
(Books) http://www.booksnbytes.com
(Jewelry) http://www.vickijean.com/new.html
(Metalsmithing) http://www.snugglewench.com
yahooID: vjean95967
-----------
"Only Irish coffee provides in a single glass all four essential
food groups: alcohol, caffeine, sugar, and fat." -- Alex Levine