Turquoise

I am a wanna be jewler and just recently found this site. I am also
a rockhound, and recently stumbled accross a small deposit of low
quality turquoise. By low quality I mean it is mainly chalk. I have
been trying to stabalize the turquoise, but am not having much
success. I have soaked it in Opticon, but the opticon does not seem
to penetrate very deep into the stone. I have also soaked slices of
the turquoise in a mixture of 1 quart acetone and epoxy. Again, the
penetration into the stone is not working. Is there anyone on the
list that is willing to share a little Any pointers
would be appreciated.

Thank,

Albert
Nevada, USA

If you would consider buying turquoise, it would save you a lot of
time and trouble and you will find it a lot easier to move in finsihed
pieces. People want a better quality turquoise. Thunderbird Supply in
Gallup, or Indian Jewelry Supply in Gallup (NM) has very reasonable
prices. All you need is a tax number. We have dealt with them since
87 and much of the turquoise is not that expensive. We were in
IJS in November in Albuquerque. Time is money and money saved is
time you could have spent developing your talent.

Hi, Jed-- Turquoise is a hydrous silicate. Every stabilization method
that I have heard of for turquoise involves first heating the
turquoise to drive off the moisture. Commercial operations then
immerse the turquoise in liquid acrylic, which the turquoise absorbs
readily due to the moisture in the stone having been eliminated. They
frequently also add dye to the acrylic bath. For years, I wondered
when browsing the southwestern jewelry outlets how it came to pass
that most of the turquoise was exactly the same color-- now, I know
that part of the reason is that they came from the same dye lot…

You might try heating the turquoise in your oven for an hour or two
to drive off the moisture, and then using Opticon. The old-timers used
sodium silicate, aka waterglass. My failing memory wants to tell me
that the protocol for stabilizing turquoise with sodium silicate can
be found in a back-issue of Rock and Gem magazine.

For myself, I prefer to cut the stuff that is natural-- the finished
stone has a different lustre, more like fine porcelain.

Hope this helps,

Lee Einer

Asfar as I know, the best methods of stabilizing turquoise are very
closely kept secrets – understandably so! I suspect that it involves
a great deal more than soaking it in Opticon or other similar
materials. Perhaps a vacuum process, or – who knows? they’re not
telling!

margaret

Dear Lee, Oops…sounds as if you were talking about Opal ! Turquoise
is a hydrous aluminum phosphate with copper. When copper is
substituted by increasing amounts of iron the coloration becomes
greener and, if the copper content is completely replaced by iron it
is Variscite. Faustite is also part of the series and involves
substitution of copper by zinc. Faustite has a very distinctictive
coloration in the yellow green shades and may be almost chartreuse.
All of these minerals tend to be porous, but variscite is less
inclined toward porosity than the others. Plastic stabilization is
very often accomplished in a vacuum oven in order to give deep
penetration. Dyeing is only necessary in the lightest chalk grades.

Ron at Mills Gem, Los Osos, CA.

You are so right, Ron-

I misspoke myself- Turquoise is a hydrous phosphate, not a hydrous
silicate. I should check my reference books before holding forth on
the chemical composition of gemstones-- it’s not my strong suit, as
you have probably surmised.

I was focusing on the “hydrous” aspect, and the fact that most if not
all turquoise stabilization methods involve heating the stone to
drive off the moisture and make it more “thirsty” for the stabilizing
agent.

You are also 100% right about dye only being used on the lowest grade
of chalk turquoise–but this does not mean that dyeing is an uncommon
practice, as most of the turquoise currently commercially mined is
chalk.

My goal was to offer some practical suggestion which might help our
friend stabilize his turquoise. To that end, here is a link that may
help –

http://lapidarydigest.com/StabilizingTurqOpal.html

Also, this is from the “Mail Bag” column of the August, 98 Lapidary
Journal–

…turqouise can be soaked in it [sodium silicate] for several days,
then heated at low temperatures in a kitchen oven until the nuggets
become bubbly. This fills in the pores and improves the color and
cutting quality.

Lee Einer

I was in a mining supply store in San Francisco some years ago. A
turquoise miner was in there buying a whole case of opticon. He said
that he treated the turquoise in the mine before he removed it. So it
was working for him. No other details were not forthcoming, though.
Rose Alene McArthur @O_B_McArthurs

Hi Jed- Just found this older posting. The material needs to be
sliced up fairly thin, less than one half inch thick and needs to be
heated (but not boiled) so it will penetrate. Maybe a week or so on
a coffee pot burner. Then it is removed from that mixture and put
onto a cookie sheet or such and heated in the oven until dry but
don’t get too hot (after painting the hardening agent on). It smells
sort of bad. You can heat it under a light bulb for the last step but it takes
a little longer.