Turquoise

St. Jerome

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Feb 21, 2005
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I just found some turquoise in new mexico. Not far from a place that the natives mined before the spanish got here. It is yellow green in color. I have pounds of it.
 

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olroy70

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always wanted to look over that area. I lived south of it, in Edgewood, and never took the time.
 

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uthunter

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Sep 7, 2010
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Only buy from a reputable supplier, research that supplier.

Most turquoise available now in either Stabilized (S, resin impregnated), Dyed (D, for better color), treated (T, heat treated to bring out better color), reconstituted (R), or is imitation (I, Dyed Howlite or Magnesite).

S - Soft material will be stabilized so it is more durable and easier to work. Think Chalk Turquoise.
D - The more blue it is, the better, richer copper content. The greener it is, less desirable, higher iron content.
T - Like many other rock/gemstones/crystals, turquoise can be heat treated to make the color(s) more vibrant and richer. Sapphires, Rubies, Quartz, Agates, and others.
R - Stone dust from the various cutting operations will be saved, dyed, and then stabilized to create stones of various types. Think of a poured counter top for a kitchen.
I - Howlite and Magnesite are just two of the natural stones that will be dyed to look like turquoise. Due to the veining of these stones, when dyed it can be hard to determine the real from the fake.

The only natural colors of turquoise are Blue, Green and White. Blue and green can be found in various places around the world. White turquoise is found in only one place in the world. A single local in California. It is commonly called Buffalo Turquoise.

Many reputable websites have pictures of the most common turquoise types, colors, and locations of where it is found.

Look for what is called Old Turquoise, less chance of it being fake.

Just remember, turquoise has been processed thru stabilization, dying, and other treatments since the early 1970's. If there is a question as to the authenticity of the stone, have it tested. Tests could range from color durability, chemical analysis, chemical testing, and many others.


Good Luck and happy hunting.

Jon
 

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Eu_citzen

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For what it's worth..

Most of it is stabilized - plastics, epoxy, opticon, resins...
It can also be accompanied by heat to help the stabilizing agent penetrate into the pores of the turquoise.

Dyed - mostly imitations which are basically turquoise-look-a-likes. I am not sure I have seen any dyed turquoise. :icon_scratch:

Turquoise is as far as I know not heated - I think it'd do more damage then good.
It may only be described as heated when there has been no other additions then heat.
 

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uthunter

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We sell turquoise beads/pendants/cabs in various sizes and shapes. The "real" turquoise is almost all enhanced (Dyed) color, blues and greens. We carry other stone beads labeled as Dyed or Enhanced Turquoise that is actually an imitation (howlite or magnesite) and they come in well over twenty colors (red, green, orange, yellow, blue, pink, black, brown, purple, tan, etc.). These are labeled as Dyed Turquoise, but when you break them open you can tell they are not real.

You just have to be vary careful when buying semi-precious/precious stone of all types. Buy from a reputable seller/dealer, don't be afraid to have a third party look at it, or get it tested.

To test if it has been dyed/enhanced: pour some white vinegar in a glass bowl, put the stone in overnight. If the vinegar is colored, then the stone has been dyed. If the vinegar is clear, then the stone is natural color.

To test for stabilization, put a few drops of acetone on the stone, if it does nothing, the stone if natural. If the stone gets soft of bubbles or dissolves where your put the acetone then the rock has been stabilized.

Heating a natural stone will darken it a bit, usually not much tho. With the majority of stone being stabilized today, heating has fallen out of favor for turquoise. Heat treating for color is still prevalent in many other types of stones. I will occasionally heat treat a particular cab or pendant to enhance the natural colors, Agates and quartz are the most common, occasionally I will do a Wonderstone or certain Rhyolite.

When I do any heat treatment, I will clearly label the piece as such. I will do certain pieces for display comparisons only and very rarely sell them.

When I get a new type of rough stone in, I will slab/slice/cube it down and do heat testing to see what the colors will do. I do custom beads, cab rough/finished, slices finished/rough, some of the rough goes through a rigorous test to see what happens. You would be surprised what I have been asked about and seen done to rock by people.
 

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Eu_citzen

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I don't know about the laws in the US..
But shouldn't dyed howlite (for example) be called just that -- calling it dyed turquoise would be a misrepresentation?

I have only heard of heat to change colours in quartz (i.e. Amethyst to citrine or very rarely Prasiolite).
Never to enhance colours? What kind of temps are we talking about? What kind of quartz?

I hate heated quartz -- much more brittle while cutting. Especially for faceting its a PITA.
But I don't work much with quartz either way.

Question, of course, is if it is worth to send it to a lab to have it tested.
I for example would likely not send a turquoise to have it tested/certified.
The test(s) would probably be more expensive then the stone.

But a 2 cts (only) heated ruby.. :blob7:
 

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uthunter

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The laws in the USA says it has to be labeled as Imitation, but there are unscrupulous dealers out there that will try to take advantage of you.

You are supposed to label a stone with the treatment you do to it, no matter what the treatment is.

Heat treating of most stones/crystals can be done after they are worked. Most heat treating can be done in a home oven or a kiln.

Here are a few links to help out:

http://ganoksin.com/blog/taogem/201...on-minerals-for-silver-solder-jewelry-design/
http://gemstone.smfforfree4.com/index.php/topic,643.msg2575.html#msg2575
http://gemstone.smfforfree4.com/index.php/topic,3392.0.html


You can do tests for color and stabilization of stones/crystals at home. They are the most accurate, but they are a starting point to narrow things down. You can also take the stones to a local college/university geology dept or in the USA the USGS and ask them to take a look. Most any dealer or geologist should be able to tell if the stone is natural or if it has been dyed.

Stabilizing a stone is not such a big deal as it used to be, more accepted due to the nature of the rock. But the process can change the color slightly itself, usually not more a shade or two.
 

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Eu_citzen

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Cool, I've never used the oven myself.

But then I've almost only heated ruby. A normal oven doesn't quite cut it there. ;D
Well, I've treated Tsavorite to.

On that link.. Is that the method you use to change the colour of the turquoise? From what locality was the turquoise?

Have you tried to see if an oxidizing vs reducing atmosphere does any difference?
 

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uthunter

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I have only tried the oven method, was able to change the color by a few shades. I think it was due more to the impurities in the stone then anything else. The turquoise came from Arizona, not sure the exact area (I traded for it).

I am looking into a laboratory oven/kiln (up to 2300C) that will will allow one to use an oxidizing or reducing atmosphere, but the prices are just a bit too steep just to go buy one that would be large enough for what I would use it for. I need one that has a chamber that is at least 12x12x12", prefer one that is 12"x12"x18".

I do need to get an oven for treating sapphires, it is just too expensive to pay someone else to heat treat them for me. I just need to convince myself that it is a good investment, even tho I won't be using it on a regular basis. As a business expense, it needs to somewhat pay for itself too.

I am about finished with an obelisk that is 6x6x24" that I want to heat treat, for personal collection. The colors are on the lighter shades of tan/brn/orange/cream/white, the colors should be several shades darker and more vibrant after treatment (I am hoping).

I did a small sample of Varacite from Hansel Valley, UT (Snowville, UT) that changed from med green to a dark green. Can't wait to get if finished into a pendant & earrings set.

You are right there a regular oven won't cut it. You need an capable of heating between 1300 - 1700C for heat treating most of your gemstones and crystals.
 

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Eu_citzen

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Thanks budd, that's what I was looking for.

I asked a couple of gemmologists many had not heard of heating the turquoise to change colour even a shade. :icon_thumleft:

I to had thoughts of such a oven, but dang no. The prices are way above what I'd think it's worth for what I do.
I just used a bonfire to heat the rubies. Packed them into a piece of fireproof brick and isolated the top with clay.
A whiskey and something to grill = perfect evening. ;D

I suppose you could just use a blooming furnace -- like they used to make bloom iron once upon a time.
They go up to around 900 - 1100 C using charcoal I want to recall. It works, just slow.
Depending on airflow you could get both reducing and oxidizing environments I suppose.

Will have to try the snow is gone. ;D
 

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Bajahunter

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Mar 26, 2011
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uthunter
Lots of good info. Thanks
I have also read that turquoise can also change color because of oils used in makeup or perfume.
Also that turquoise left in the sun can dry out, causing cracks and changing the color.
Is this true or just an old rock hounds tale?
 

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uthunter

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The oven I am looking at goes for about $7000. A bit much right now for a "just because toy" as my wife puts it.

I found a source for smelting metal in a microwave, wonder how it would work on stone. I don't think my wife will let me use our microwave tho, just to test it out. She said if I want to try the metal smelting for gold and silver, then we will need to get a different microwave.

I think the same setup or something similar would work for stone as well, just not sure how even it would heat. Also the heat needs to slowly raised from about 200F to upwards of 600F and held for a period before it is slowly brought back down.

Most gemstones & crystals when worn as jewelry can be affected by oils from your skin, makeup, perfume, etc; especially the softer material gemstones such as turquoise or pearls. Many precious gemstones will fade or discolor when exposed to sunlight for a long period, or when exposed to the oils from your skin, makeup, perfume, etc. The oxidation and discoloration of metals on jewelry can discolor or stain gemstones and crystals as well.

The products commonly sold for cleaning of jewelry can have some seriously adverse effects on the jewelry as well.

Turquoise can fade, crack, flake, discolor, and more when it is left exposed to the sun and weather for an extended period of time. When the stone is stabilized, it is impregnated with a glue of sorts, it becomes much stronger and harder. This will allow the stone to resist drying out, weathering, cracking and such.

The various treatments used on precious gemstones is becoming more common for many types of semi-precious and precious gemstones, especially the ones that are becoming rare and ones where the best material is mined out and that is left is the material that used to be discarded as too low a quality to be of any value. Stabilizing and enhancing the stone turns it into a workable stone and one whose color is rich and vibrant.
 

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Twisted One

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Just to chime in, I have a couple pounds of raw turquoise given to me from a friend a long time ago, and he got it at an estate sale or something. I used to do a little bit of jewelry making, but never worked with raw turquoise, and never messed with this because it is so soft.

So I have no idea if any of it has been treated in any way. This will be something I will have to look into more.
 

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uthunter

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Since the late 1960's, various treatments have been available for most gemstones. Turquoise was/is a popular one since some types were always in short supply and the more common types were then dyed to match the uncommon types.

Stabilizing and enhancing (dying) were the most common treatments. You can use the vinegar, broken stone, or scratch test methods to check your stones for enhancement. All three test methods can be destructive to your stone by the way.

Not many consumers care if the stones have been treated as long as they look good.
 

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St. Jerome

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Feb 21, 2005
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I Have heard of this buffalo turq. It is white magnasite from what I hear. No, this turq I found is open to claim. It is hard for the most part but almost like a flourecent lime green. And some army yellows. It has blood red webs. It almost looks white but is definitely not. It is real untreated 100% natural turq. I did not buy it. I collected it legally from public lands. I have researched my rights and the status of the location and it is available. Turquoise is not stablized or enhanced unless u get it from china or from some scamer dealer. I would never buy treated turq and I have been working with it for 15 years. I am not an expert on it but I know what im buying and selling. As far as buying I used to trade work for turq. As far as selling.... I found a unique deposit and am more inclined to work the rock myself. I could trade you a chunk for something. You decide. I wont put a price on it because I found it and can get more whenever I want. PM me and we can talk. I can send you photos and what not.
 

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uthunter

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I am always interested in trading for different stones. I will send you a list of the different stones I have (I have pics for most of them). I have most in bulk or slabbed ready for cab or pendant work, or polishing for display. I buy rock in bulk then cut down to different sizes. I am working on putting up a website, as time allows.

If you buy turquoise in rough form and the pieces are relatively large, then there is a chance that it may not be treated by any method. The stone available to the jewelry trade and small time lapidary hobbyist is more than likely treated by several methods, including stabilization, enhancement, reconstituted, etc.

There is a true white turquoise and it is called Buffalo Turquoise. White magnesite will look close, and it is often sold as turquoise, whether it is white or dyed. There is a distinct chemical difference between the two. But then they could be reconstituted turquoise, still turquoise but in dyed un-natural colors.

I have three pieces of that is supposed to be white buffalo turquoise, there is a very pale green/blue shade to part of each piece. The guy I got them from swears up and down the pieces are real, but I doubt they are turquoise and they are not worth having them tested.

I have several types of beads that are labeled as dyed turquoise (yellow, pink, fushia, orange), but I question these too. They look just like the four hundred pounds of dyed magnesite beads I bought, same colors and patterns.

Turquoise has been stabilized and enhanced since the mid 1970's, the process was discovered and worked out in the 1960's by a man herein the USA. I have several pieces of old turquoise from the 1970's that are in and came out of jewelry, and these pieces are stabilized.

There are a number of places here in the USA that do stabilization and enhancement of turquoise and other stones. The majority of the product comes from Africa, Mexico, Brazil, Pakistan, Afghanistan, China, Taiwan, and Australia. You can even do it on the stove in your house with a pressure cooker.
 

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Twisted One

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Would you be willing to give me an idea of what some unknown raw turquoise is worth if I posted a picture?
 

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