Re: [Orchid] Green Turquoise….

by Canyon Cassidy on October 13, 2009

Hi there, this is Canyon Cassidys of the Nevada Cassidys, my family originated the Stone Mountain Turquoise claim out in Lyon Co. Nevada.

The colors of turquoise-

For discussion I will use my own material.
Stone Mountain Turquoise happens to have a large variety of color…
Most of all varieties of “green turquoise”.

In common place, most people associate the word “turquoise” with the common color centered somewhere between blue and green. The uncommon wisdom here is that turquoise usually not this color. From our research it appears that there are only a handful of mines that commonly produced the typical shade associated with turquoise in large amounts. Persian, tibetan and chinese, sleeping beauty and so on. Even though these turquoise mines also produced amounts of greener turquoise over the years.
Many of the smaller mines out there  produce “only some” of the color shade associated with turquoise you might find in inks, dies or colored pencils or pictures of the Bahamas etc.

For example, damale has a great deal of green because it is  mixed with variscite to produce a strange creamy green color. The copper bond in those stones are not like that of turquoise and show shades of color that do not occur in turquoise. Most of the pure green turquoise has a hue that is actually brown. Variscite when blown up on a photo of projector screen will show almost fluorescent shade of yellow and/or lime green. These colors are created by a chemical bond that is nearly all copper. Turquoise is always a less dominated chemical mixture.

Thinking Green – Iron the universal bonder

At Stone Mountain the host rock has a huge amount of iron, which runs in veins and knobs throughout the deposit. So we find green turquoise veins following the iron all over the deposit in a very random spiderweb like pattern. This sort of coloration caused by the iron can span out over the hillside for a very large distance, usually encompassing the whole claimed area and going far beyond the turquoise veins.
Iron as it turns out is the “universal bonder”. Iron can and does pull nearly all minerals into a chemical bond. So any turquoise deposit that has a good amount of iron is likely to produce great varieties of color and/or green shades of turquoise.

This fall I went through Berkeley and displayed some turquoise to a few jewelers in town. One of the jewelers is a gemologist and as soon as I showed him the stones he immediately went into a dictation about how iron makes turquoise harder. And that the iron is responsible for the green color, and that when turquoise has a little more copper than iron in the bond it comes out on the blue side of the spectrum.

Summary:
The colors of turquoise are always a reflection of the chemical reactions that took place in the very spot  where the stone was extracted. One thing we notice at Stone Mountain Mine is that when following a turquoise vein the color of one vein can change drastically to a totally different shade in just a few inches then revert right back to it’s originally discovered shade. This shows us how the influences of iron are dominant. Where ever the iron is condensed you are likely to see some green chemical reactions that took place in the stones found there.

Here is a typical green turquoise stone from Stone Mountain Mine,

http://nevadacassidys.com/store.php?search[terms]=green&search[mode]=any

Cheers
Canyon Cassidy
Lapidary Artist / Miner
Nevada Cassidys

{ 3 comments… read them below or add one }

Canyon Cassidy July 22, 2012 at 6:20 pm

Interesting question, personally I have never stored turquoise in such a manner. Turquoise will not lose it’s color so easily. And the color will vary after it soaks in oils or water from being worn. Some of the turquoise from Stone Mountain for example, are actually slightly pale before they are worn. Then after someone where the stone for a certain amount of time it soaks oils and water and begins to darken.
Then if this person decides to not wear the stone for awhile that darker color will slowly fade with time.
And then if they decide to wear it again, it will still darken once more from soaking oils and water. Essentially Turquoise will not lose it’s color like opals do. Some varieties of turquoise seem to vary in darkness depending on the local environment it is in. The Water technique you mentioned might do the same as if it is constantly worn. However a possibility that the water may pull the color out of the stone over time. The best recommendation I have is to keep the stones out of the sunlight. And if you are going to try the water technique, use spring water as distilled water may actually deplete the minerals in the stone.

Fabrizio Colonna July 22, 2012 at 4:26 pm

Just yesteday I’ve placed an order for rough turquoise.
Can you tell me if putting natural turquoise in demineralized water can preserve it from dehydration and color alteration?
I found some Cananea turquoise nuggets in a jar filled with fluid like water, but really I don’t know what kind of product it is.
Can you help me?
Thanks.
Fabrizio Colonna – Italy

william Pickerd July 15, 2011 at 5:13 am

looking for green turquoise, cut into slabs 1/8 to 3/16 thick large enough to get a 1/2 x 1″ piece out of it, can you help? Bill

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