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Testing To Destruction - Mojave Turquoise

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Michael S Hoover - Redrummd
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« on: June 14, 2010, 10:18:09 pm »

I tend to believe that there are a lot of people and companies engaging in fraud in regard to a lot of stone being sold as "real" when in fact it is far from being even mostly stone. 

So I bought a cheap "Mojave Turquoise" set in a costume jewelry setting just to test to destruction. 

The first picture shows the cab out of the mounting.  Look carfully at the girdle and you can see that the finish is sprayed on!  I really would like to know what they used as it looked great and I really thought it was just the polish on the cab.  The weird part is I did a test polish that is shown in the last picture and it sands and polishes very easily using ZAM for the final polish.

The 2nd picture shows the cab after i drew a circle on it with a microtorch.  With very little heat the green dyed color basically evaporated out of the material.

The third picture shows the cab actually burning which is really difficult with real stone!  The stuff burning is the plastic resin that was used to cement the pieces of stone together.

The fourth picture Shows the back of the cab up against the known sample of the stone I beleive is being used for this process - Howlite.  I personally do not believe there is any turquoise of any sort in the "Mojave Turquoise".  I bought the blue Howlite (AKA Magnesite) to do a low cost knife that looked like turquoise for a request from one of my regular buyers. 

Howlite is also sold in its natural state, sometimes under the misleading trade names of "white turquoise" or "white buffalo turquoise".  I beleive that if you ever pin down those selling this and several other claimed turquoise stones that they will fall back to this as their origin for calling the material "stone" and "Turquoise"  The definition noted above is directly from Wikipedia, the free online encyclopedia.[/b]

The last picture is of the stone where I cut and polished it.  It does cut, sand and polish easily but you need to know what you are really buying as in my opinion it is being fradulently sold as "turquoise".





* Polished Mojave Turquoise before destruction test.JPG (140.8 KB, 1024x768 - viewed 127 times.)

* Just a touch of heat - green color evaporates out.JPG (170.72 KB, 1024x768 - viewed 124 times.)

* Mojave Turquoise on fire.JPG (163.16 KB, 1024x768 - viewed 112 times.)

* Mojave Turquoise next to know Howlite dyed blue.JPG (168.29 KB, 1024x768 - viewed 107 times.)

* Polishes real easy with ZAM.JPG (141.12 KB, 1024x768 - viewed 111 times.)
« Last Edit: July 03, 2010, 06:26:02 pm by Taogem » Report Spam   Logged

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Taogem
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« Reply #1 on: June 15, 2010, 02:16:10 am »

The only couple of purchases of this kind of material for me is the Purple Turquoise/Bronze, Confetti, and Orang Coral.. All are pressed resins.. Like Amanda mentioned in another thread... "Stabilized, Dyed and chemically enhanced".

That really does sum up these different kinds of pressed materials.

Remember, this Mojave Turquoise is faux.. I know it is not generally stated, but some sellers do clarify that.

Philip (Steel and Stone) shared how the company Thunderbird describes this material they sell.

"Many people are surprised to learn that only about 25% of turquoise is usable or desirable in its natural, untreated form. Most untreated turquoise is a fragile, porous stone with a tendency to undergo changes in color when exposed to light, perspiration, oils, and detergents. While turquoise is hard enough to be considered a gemstone, it is comparatively soft. The following are various treatments done to turquoise to keep it from fading or crumbling.

Stabilized
Impregnated with acrylic or epoxy to harden the stone and enhance the color. Stabilized turquoise will not change color over time. "

I think what has unfortunately happened to you is that you happened upon someone selling straight up junk ! Especially considering they spray painted on a polish.

I don't believe any of this faux material would hold up under even minimal torch heat though.. I would expect the same reaction as you got from applying even a minimal amount of heat to it..

Excellent pictorial showing your "test to destruction" !  yes

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« Reply #2 on: June 15, 2010, 03:58:38 am »

George, do you know for a fact that the Vietnamese Orange Coral is not real Coral?  I always thought it was the real thing.  I have never noticed any hot resin smell when working it, like i do when i cab some of the man made, compressed, or stabilized stuff.

Mark
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« Reply #3 on: June 15, 2010, 06:57:37 am »


So I bought a cheap "Mojave Turquoise" set in a costume jewelry setting just to test to destruction. 


I am a firm believer in "You get what you pay for." 

If you buy cheap, you'll get cheap in quality.

If you buy from a reputable seller or company that discloses what their stones are made from and their origins, then you are probably more likely to get good quality material.

The cheap stone that you tested was probably the cheapest stuff there is quality-wise.  Mostly resin, barely spent time in a dye bath, and contained very little usable stone.  Truthfully you are right with this particular sample tested - probably not even close to any real turquoise material in there - and not made with a heck of a lot of skill either by whoever put the stone together.

People say Howlite and Magnesite are the same material.  Chemically they are not, though they have similar properties:

Howlite:  (Ca2B5SiO9(OH)5) (Wikipedia)  (Hardness 3.5)

Magnesite: MgCO3 (Wikipedia) (Hardness 3.5-4.5)

Both will take dyes and stabilization and can be cut and polished with about the same hardness.  Dyed Howlite is sometimes referred to as Magnesite, which just adds to the confusion between the two stones within the gem trade.

Turquoise of course comes in a multitude of varieties and treatments. 

Turquoise:  CuAl6(PO4)4(OH)84H2O  (Wikipedia)  (Hardness 5-6)
Blue colors are associated with higher copper concentrations and the green colors are associated with iron impurities.  Turquoise with a very light blue to almost white to it has a proportionately higher aluminum content to it.

Judging by the varying hardnesses of the stone varieties, I would think you would know which one you were using when putting it to a wheel for polishing or grinding.  Like limestone, Magnesite should bubble under an acid treatment because it is a carbonate.  Though since it has been dyed and stabilized it might not fizz up under the acid.

I would say the material being sold cheaply is going to be one of the softer stones.  The fact it is being marketed as "Turquoise" When it contains none means you don't have a reputable seller.  If they were of decent repute they would state the stone was made with howlite or magnesite that was dyed.

If you are buying from someplace like Thunderbird or from a seller that has a good reputation such as Mijo730 you are probably getting material with actual turquoise in it.  Stabilized, Dyed and chemically enhanced  Turquoise.

The testing you put this "cheap stone" through was informative and certainly exciting to read about.  I'd like to see a piece of real turquoise and a piece of the mojave turquoise from a reputable seller go through this same test.
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« Reply #4 on: June 15, 2010, 07:06:01 am »

LOLOL MIchael cool test:)  Domo Arigoto Dr. Destructo:)

Informative post Thanks:)
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« Reply #5 on: June 15, 2010, 03:29:29 pm »

George, do you know for a fact that the Vietnamese Orange Coral is not real Coral?  I always thought it was the real thing.  I have never noticed any hot resin smell when working it, like i do when i cab some of the man made, compressed, or stabilized stuff.

Mark

Have not actually cabbe either of the two slabletts purchased.. One seems to show obvious resins on the edge. The second one appears to show some resin, but could well be broken fossil too..



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