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Untreated Peruvian turquoise rough


#1

I just ran across some Peruvian Turquoise rough that is totally
natural and untreated. My understanding is that this came out of the
ground a minimum of 35 years ago. I’ve started cutting it and it’s a
beautiful color, a kind of pastel, mint, blue/green. Some is zoned
both blue and green. Of course because it’s untreated, it will
darken if with wear.

I’m wondering if anyone has run across this material before?

Even on line, the only references I find are about ancient Incan
jewerly.

One other thing do people know of any good lapidary list servs or
blogs that one can join? I used to belong to a few and several have
dropped out of sight.

Derek Levin
www.gemmaker.com


#2
One other thing do people know of any good lapidary list servs or
blogs that one can join? 

You might try joining the AmericanTurquoiseMines or AllTurquoise
Yahoo groups. There a bunch of “good old boys” who have been in the
turquoise trade since the 1970s and beyond. For lapidary there is the
Lapidary list Yahoo group. It’s not real active but a good place to
post a question and have some lapidary old timer’s respond.

Rick Copeland
Silversmith and Lapidary Artisan
Rocky Mountain Wonders
Colorado Springs, Colorado
rockymountainwonders.com


#3

I’d suggest the United States Faceters Guild, too. They host a free
mail site that is quite active, although it is generally restricted
to faceting as opposed to general lapidary. Yahoo! Groups;
USFGfaceterslist

Wayne


#4

Derek,

I don’t know if this is what you’re looking for but I just found it
myself earlier today & joined the forum. gemstone.smfforfree4.com/
It’s relatively new and appears to be gaining more interest and
discussion lately.

There’s also this, thecarvingpath.net, predominantly netsuki carvers
(awesome!!) but a few gemstone carvers and some interest in lapidary
in the mix.

And of course, Bob Keller’s rockhound forum rockhounds.com/rocknet

Hope someone else will know of even more, I’m interested too. CaroL


#5

Are you sure it is actually turquoise? The trade name “Peruvian
Turquoise” has been a common misnomer for Peruvian unsilicated
chrysocolla that cuts similar to turquoise. Although there are large
copper porphyry deposits in Peru they have not historically produced
turquoise. Have you sent it to a lab for testing? The blue/green
zoning sounds more like chrysocolla than turquoise.

Richard M. Shull, G.G.
outofourmines.com


#6

To Richard Shull,

Yup. It’s definitely turquoise and definitely from Peru. I’ll send a
photo to your web page.

Derek


#7

There is a source of Turquoise at Chukikamata copper deposit and
blue/green zoning would not be a red flag for me; but as a trade
name “turquoise” is abused very often, so testing is a good advice.

Leonid Surpin
www.studioarete.com


#8

If it is gem quality turquoise it will not change color from wearing
it.

Lloyd.


#9
If it is gem quality turquoise it will not change color from
wearing it. 

Even gem quality turquoise will absorb skin oil over time and
darken. But only if worn against the skin, and only if you don’t have
it stabilized. (Which is far from impossible, and will make it easier
to cut without cracking.)

All turquoise is porous until stabilized, regardless of quality.

Lindsay Legler (Who only likes carving and cutting stabilized or
reconstituted stones, because they don’t break or discolor )


#10
Even gem quality turquoise will absorb skin oil over time and
darken. But only if worn against the skin, and only if you don't
have it stabilized. (Which is far from impossible, and will make it
easier to cut without cracking.) 

That is not correct. Gem turquoise does not require stabilization
and it can be safely worn against the skin. But it must be gem
quality to do that.

All turquoise is porous until stabilized, regardless of quality. 

This is a fairy tale created to justify stabilization of turquoise.

Leonid Surpin
www.studioarete.com


#11

This is a fairy tale created to justify stabilization of turquoise.

Tell me why the Aztecs oiled and waxed their turquoise, then?

And explain how, with the chemical/geological/gemological make-up of
turquoise that it can be hard enough? It’s very structure is porous
in nature.

Turquoise that is that hard and non-porous is the fairy tale. I’m
willing to suspend disbelief enough to say that there may be some
VERY RARE pieces that have this quality, but I would also venture to
say that no one on this list either has access to them or can afford
them. And they were mined over 70 if not 100 years ago.

Sorry Leonid, on this one, you’re wrong when it comes to anything
that can realistically be obtained. And if you sell someone
turquoise that you did not personally dig up and say that it’s not
stabilized, treated or altered, you’re misleading your customers.

Lindsay Legler
Dreaming Dragon Designs


#12
All turquoise is porous until stabilized, regardless of quality. 

An absolutely true statement, but it suggests to some degree that it
must or should be stabilized. Turquoise is a porous stone, period.
The harder it is, the less it it is a factor, but it is still porous
always. Speaking as a one time big time turquoise buyer, cutter and
trader, back in the dark ages…

http://www.donivanandmaggiora.com


#13

Excerpt from an earlier post.

Even gem quality turquoise will absorb skin oil over time and
darken…All turquoise is porous until stabilized, regardless of
quality. (Which is far from impossible, and will make it easier to
cut without cracking.)

Lindsay Legler (Who only likes carving and cutting stabilized or
reconstituted stones, because they don’t break or discolor )

Lindsay, it seems like a strange approach to turquoise to want it
only stabilized for the sole purpose that the color remains
constant. If a stone cracks it’s usually because it had a crack in
it or it has been treated too roughly. Only a few stones crack
spontaneously, like opal, that can be unstable. I made the original
post about this material and now that I’ve cut quite a few cabs, I
find that it’s quite attractive and takes an excellent polish.

For those interested, my testing of the material shows a range of
hardness between 4 and 5 mohs. Most is 5. Based on the responses
I’ve gotten off this forum privately and publicly, I’ve concluded
that this is very unusual material and not readily available.
Several very knowledgeable people originally even voiced skepticism
that Peruvian turquoise actually existed. But I double checked the
source with the person who originally imported it and found that it
was absolutely from Peru. Also one look at a photo of the finished
stones has convinced every skeptic that it is turquoise, not a form
of chrysocolla that is frequently called Peruvian turquoise. That
other material is a copper ore and much darker.

It seems from my reading that the color of turquoise is generally
influenced by the relative amounts of copper and iron in the stone.
As to the color of this material, it is in the pastel ranges of blue
and green, and tends more towards the green. It’s quite vibrant in
color and some has a nice matrix, although I’ve cut most pieces
without matrix. The colors of the matrix can range from brown
through a darkish olive green to even a bright red and some of the
turquoise has splashes of red in it. It’s also yielding some larger
stones even up to and potentially through the 40 mm range. I have
not yet attacked the largest pieces of rough. It also cuts some
scenic stones.

As to changing color, I’ve cut a piece to wear myself. Before too
long I will be able to tell if it darkens with wear.

If, however, it does darken by absorbing the oils from my skin, I
will consider it rather a nice interaction between me the wearer,
and the jewelry I choose to wear. I suspect the color will still be
attractive. It seems that there are still a great many people who
like the natural untreated stone, go out of their way to find it and
pay a premium to get it. I’m also pretty certain that some of the
harder turquoises will not take stabilizing.

That’s why it seemed odd to have the comment that turquoise should
be stabilized. If it does impregnate, it then becomes largely
plastic. I may be a minority in this, but I prefer my stones to be
stone and mostly untreated. There is something more elemental about
that.

There is a wide range of what is stone these days with multiple
treatments that go from heating to totally fake. The real problem is
that there is way too much that is intended to deceive. To me the
beauty in the stone is in large part that it is stone. Although I’d
rather have all natural, alterations like heat treating and even
irradiating still leave the finished product a stone. Heat and
radiation are after all alterations that can actually happen in a
natural situation, so it remains stone. That is important to me,
though I acknowledge that it is a personal preference.

What should not be a preference is full disclosure of treatments. I
think there are many reasons for that, but one of the main ones has
to be an extremely important element in jewelry that should not be
overlooked. That is that probably most often, the piece of jewelry
is connected with sentiments. It is so frequently associated with an
occasion or the commemoration of an emotional bond.

How many times have I seen stones that people show me that were sold
at a relatively high price but that are not what they were said to
be at sale. Sold through deception. Yet the person who is wearing it
believes that it is authentic and commemorates something important
in her life. To me somehow a deep emotional bond, bound up with a
deception, bases the whole set of transactions, emotional and
commercial, on inauthenticity.

Most people who buy turquoise do not know that it has been
stabilized, or even worse reconstituted making it mostly plastic.
Even worse still are those who end up with just plain fake. I prefer
my symbols of emotion to at least be firmly planted in the truth. I
actually like them from the earth. Of course plastic is made from
petroleum which began it’s life as a natural product. Sorry to go on
so, I guess in the final analysis as long as there is disclosure
customers can make up their own minds, but I prefer untreated
turquoise.

Anyway, if any one wants to see a photo of this turquoise just email
me off list.

Derek Levin
www.gemmaker.com


#14
And explain how, with the chemical/geological/gemological make-up
of turquoise that it can be hard enough? It's very structure is
porous in nature. 

We can talk about 3 basic types of turquoise.

One is called Common Turquoise. This is what is used for
stabilization process. It is soft and chalky and would not last long
without stabilization.

Then there is Gem Turquoise. It is very old ( in geological terms )
and become silicified ( same way like petrified wood ) and this
turquoise could approach quartz in hardness. When it is perfect blue,
we have famous Persian variety.

The third type is called semi-turquoise. Semi-turquoise could be a
long discussion, so I will only give one example. Iron is a common
admixture in turquoise, aka Ferro Turquoise, which can form an
isomorphic row ( various compositions ) with Chalcosiderite.
Henwoodite is an example of that.

Trade varieties like spider-web and others are not part of this
discussion. They properly should be called Turquoise Matrix.

This is in no way complete description of Turquoise. Many volumes
can be written about it and even than the subject would not be
exhausted.

Leonid Surpin
www.studioarete.com


#15
it seems like a strange approach to turquoise to want it only
stabilized for the sole purpose that the color remains constant. If
a stone cracks it's usually because it had a crack in it or it has
been treated too roughly. Only a few stones crack spontaneously,
like opal, that can be unstable. I made the original post about
this material and now that I've cut quite a few cabs, I find that
it's quite attractive and takes an excellent polish. 

I generally work with reconstituted Turquoise. That would be what I
meant about not cracking. I would NOT want to try carving
un-reconstituted turquoise with a flexshaft and steel burrs. The
advantage to stabilized is not discoloring. Sorry that I wasn’t
clearer, I was a bit tired when I wrote that.

Lindsay


#16
Many volumes can be written about it and even than the subject
would not be exhausted. 

Only one is needed - Pogue’s “The Turquois”. To this day the
definitive volume for the overall picture of what turquoise is about.

http://www.donivanandmaggiora.com


#17

Hello Orchidians, I’ve just returned from a camping trip and catching
up on my e-mails, the turquoise discussion is interesting to me as a
turquoise mine owner. We never use dynamite during our mining
practices and we never stabilized our turquoise. The addition of
synthetic resins and glues deaden the stones natural qualities. We
do have a range of types and quality. We are glad to share natural
turquoise with folks who appreciate its natural qualities.

Suzanne Cassidy
Stone Mountain Turquoise