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Author Topic: Colored "Crackle Quartz"  (Read 2544 times)
Aster
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« on: April 19, 2011, 12:27:23 AM »

I ran into several examples of "Crackle Quartz" in bright colors, used in a line of jewelry at an Etsy store. (Links to a couple of the rings are here and here, so you can see what I'm talking about.) 

Despite the artist's description, which implies these stones are "natural", I assume they're treated and dyed. I'd like to understand *how*.  What causes the crackling?  How are these stones dyed?

I have to admit I kinda like them, even though the implication that they are untreated is very troubling.  I'm fully aware that they're treated, but the result is bright and colorful and...fun.  Cheesy 

Can anyone tell me how they're created?

Thanks!

~ Aster
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Jim A.
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« Reply #1 on: April 19, 2011, 12:46:31 AM »

Take a small boiler and put water in it. Put a handful of marbles in - bring it to a boil. Remove from heat, pour off the boiling water & replace it with cold water. If you want colors add food coloring.
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Jamey S.
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« Reply #2 on: April 19, 2011, 01:28:43 AM »

Yes, they are treated. It is done by heating the quartz to extreme temps and then quenching it in liquid to cause the cracks. Then it is soaked in dye and some have the surfaces sealed where others do not and the dye can leech out.

The real issue here is it seems some are now using synthetic quartz and what is known as quartz glass(most typically what is being used in the fakes) which is where they take synthetic quartz and natural quartz scraps and melt them down to make essentially a high silica content man-made glass product, it cuts beautiful gemstones when faceted, but they are using it because it is sooooo fricken cheap even compared to just clear lower quality natural quartz and is more readily available and in many colors as well! I've only examined three of these "fakes" so far but have talked to suppliers in the know who have seen many many more trying to be passed off. Kind of pathetic really, just to save pennies per carat, lol. This same quartz glass is being passed off as quartz in both beads and faceted stones as well! A lot of these bi-colored quartz stones, odd colored quartz like deep blues and reds etc, are all nothing but this quartz glass but being sold as natural quartz or heated quartz by lots of Thai and Chinese sellers on Ebay as well as in bead shows and all over the place! Lots of US bead sellers on the ent and in B&M(brick & mortar) stores are selling them as well under incorrect disclosures and representations.

Lots more BS going on, especially with all these agates and jaspers from China on Ebay and the like... article coming soon on all of this. Everything from dendritic/plume/moss agates to picture jaspers and all kind of stuff are being totally faked from everything to just mixed pulverized rock into resins/epoxies and tossing in chunks and dyes to actually some how adhering screen printed type things onto porcelain/ceramic like cabs and then glazing them over and polishing so they look like the real thing(R2 discovered this one) to just dyes with resins to some things that will just blow your minds once I get the testing and stuff done!
« Last Edit: April 19, 2011, 01:31:53 AM by Jamey S. » Logged

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« Reply #3 on: April 19, 2011, 12:35:32 PM »

some things that will just blow your minds once I get the testing and stuff done!

Wow!  That's going to be some article!  I can't wait to read it.

I knew these particular "quartzes" were treated and dyed, but I didn't realize the actual "quartz" material was also being faked.  I mean, other than "cherry quartz" and "volcano quartz," which I'm aware is man-made glass.  And I've gotten to the point where I don't trust most beads labeled "agate" or "jasper" (which is sad, since there are so many beautiful *natural* stones out there), and I know that quartz doesn't naturally occur in the incredible rainbow of intense colors available now.  But I had no idea about the lengths vendors are going to, like screen printing ceramic cabs!  That almost seems like it would be more labor intensive to make it profitable, but obviously not, or nobody would do it. Undecided

Is there any way for an average consumer to tell the difference between natural and synthetic quartz and other stones?  Or does it require gemology training and special equipment?

~ Aster
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« Reply #4 on: April 19, 2011, 01:51:22 PM »

Jamey and others may have more info. But my view is of the sad situation is that: unless you know and trust the cutter's knowledge, you are going to be safer assuming that any rock crystal, citrine, smokey quartz, prasiolite, amethyst, ametrine, rose quartz and blue quartz are synthetic.

A polariscope can be handy in seeing twinning patterns (boundaries where crystals grow together) found in natural quartz but missing from most hydrothermally-grown quartzes (though it is possible to use multiple seed crystals to grow synthetics which shows twinning boundaries). However, in small cut stones, and depending on how the rough was oriented when cutting, it is going to be even more difficult to look for diagnostic features of natural vs. synthetics without special equipment. There is an overview of the problem here.

There is plenty of natural material, and it is an outrage that energy is consumed in manufacturing these synthetics primarily because mass-market jewelry manufacturers prefer large quantities of identically colored stones, and because those manufacturers and the retail jewelry, catalog, department store and other outlets sell 'em as "natural" gems and don't bother to (wink-wink) look to deeply into the origin of the gems they sell.
« Last Edit: April 19, 2011, 02:05:10 PM by rock2dust » Logged

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« Reply #5 on: April 19, 2011, 02:29:47 PM »

R2 is correct. That is the sad assumption that must be made any more. Amethyst, citrine, prasiolite, smoky quartz, ametrine(especially), rose quartz, and rock crystal, oh, and blue quartz, are all heavily saturated with synthetics. And for the normal Gemologist it is not typical an ability to determine the difference between the natural and synthetic ones. And most consumers will NOT pay the premium price for a lab report on quartz, lol.

Also, keep in mind that NOW just because an Amethyst shows twinning, it does NOT make it natural, they can now produce hydrothermally grown twin crystals.  Undecided Angry So while it can be a bonus, it is not necessarily diagnostic any longer.

You're only real hope is that the quartz piece has natural inclusions, hence why pieces with inclusions are now more highly valued. That part of the seed crystal was mistakenly left in the cut stone. That you find the stereotypical bread crumb inclusions that signify synthetic, as well as a few other remote inclusions.

ONLY buy quartz if it is from a truly reliable source. Even from reliable Jen will not buy it any longer unless it shows at least partial crystal faces and such. Just too iffy. And unless you can prove without a doubt it is 110% natural, people just will not pay much for them anyways. :/.

Another key sign is if the price is too cheap. I can tell you top quality colors in amethyst cost $3-$4/ct+ for the rough stone, figure a 20% yield just to be safe, so in order to get a 5ct finished stone you would need approximately a 25ct piece of rough, 25ct x $4/ct = $100 for that piece of rough. Now figure even an poor overseas cutting charge will be like $3 for the cutting and once figure in shipping and customs, more like about $8-$10. So, up to $110. A good cut, figure far more, along the lines of $30-$60. USA cut figure way more, lol. But even at $110, let's say they buy the rough in bulk and get it for 50% off because they bought a ton or something, even @ $2/ct x 25cts = $50, so at a minimum $60 for a 5ct stone. Now explain how they can sell that stone for $.99-$19.95 or even $29.95? They can not do so. So that leaves a few things in play, treatments or synthetics, or in some rare occasions very old stock that was gotten cheaply once upon a time, or they mined it personally by hand themselves. Doubtful all these Ebay sellers are using old stock or mined the rough by hand, lol. Even going to a mine and paying to dig, it is not super cheap!

So, unless your transparent quartz piece has a factual provable pedigree, it is not worth much, lol, unless a custom USA cut, then it is the cut that makes it valuable and not the actual material in this instance.
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« Reply #6 on: April 19, 2011, 03:45:45 PM »

Thanks for the great -- and very sad -- info and the link to the article.  I honestly had no idea it was THAT bad.  I mean, I know there are a lot of synthetics and fakes out there, but I just didn't realize the extent of the problem.

What about quartz points and other rough?  It's not hard to find clear quartz, amethyst, citrine, and smokey points -- even small rough points drilled as beads or rough that has been "hammer faceted".  I know amethyst, citrine, and smokey quartz is often treated to enhance and intensify the color.  Does that happen to the pieces sold as natural points?  Are they also fakes?  Or is the problem confined to cut stones? 

~ Aster
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« Reply #7 on: April 19, 2011, 03:58:24 PM »

Quartz points can (and are) manufactured simply by grinding the hydrothermal stuff to shape, and sometimes multiples are stuck together to form more-or-less natural looking clusters. This use of synthetic isn't as common as in the faceted stones, however, and the real things give you more to work with as far as an ID (cut examples are going to cut through the structure in a way that natural crystals don't, plus you have a base to look at, etc.).

It is much easier to identify the faked agates and jaspers. No one has yet figured an economical way to synthesize crypto-crystaline quartz that I'm aware. So you are mostly dealing with glass imitations (flint/quartz glass), or dye jobs. Just being familiar with the species of agate or jasper is going to give you huge clues, too. Frankly, I'd far prefer a nice "Amethyst Sage" agate to a traditional "amethyst" at this point. I like the inclusions and pictures in "Amethyst Sage", though you still have to look out for unnaturally colored dye (not common, but could happen).

But you can also still find natural xtals of quartz, amethyst, citrine, etc. at reasonable prices (or dig your own), and have someone facet them for your own use. Like Jamey said, the value is mostly in the cutting anyway for most quartz. I also agree with him on liking natural inclusions.
« Last Edit: April 19, 2011, 04:02:39 PM by rock2dust » Logged

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« Reply #8 on: April 19, 2011, 10:11:12 PM »

Quartz points can (and are) manufactured simply by grinding the hydrothermal stuff to shape, and sometimes multiples are stuck together to form more-or-less natural looking clusters. This use of synthetic isn't as common as in the faceted stones, however, and the real things give you more to work with as far as an ID (cut examples are going to cut through the structure in a way that natural crystals don't, plus you have a base to look at, etc.).

*snip*

But you can also still find natural xtals of quartz, amethyst, citrine, etc. at reasonable prices (or dig your own), and have someone facet them for your own use. Like Jamey said, the value is mostly in the cutting anyway for most quartz. I also agree with him on liking natural inclusions.

That seems like a lot of work to create a "natural" point.   Undecided

I think I'm familiar enough with the quartzes to be able to tell a synthetic cluster from a natural cluster.  At least, I *hope* I am.  And I agree with you about inclusions -- especially internal rainbows.   Cheesy  In general, I don't want to cut this kind of stone -- I greatly prefer the natural crystals.

I'm more nervous about being able to spot the dyed agates and jaspers  Sad  although I do agree with you about their natural beauty.  I'm particularly partial to kambaba jasper at the moment.  And fire agate, of course, but I think that's in a class of its own.   Wink
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« Reply #9 on: April 19, 2011, 10:45:53 PM »

That seems like a lot of work to create a "natural" point.   Undecided


Yeah, you'd think so. But if you are sitting around a Guangzhou shop or factory with the equipment at hand and easy access to cheap hydrothermal, it might make sense (especially since they often sell the counterfeits for cents per gram to shady dealers who mark them up and resell as genuine).

Fake Herkimers of this sort have been "improved" from any old quartz (synthetic or not). It doesn't cost much more to get points from reliable people who dig 'em or who have proven relationships with people at the source.

The stuff does get shipped to and sold at even the big shows (i.e., Tucson). This blog occasionally posts pictures of the various fake minerals that make the rounds.
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Lee Little
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« Reply #10 on: April 20, 2011, 01:41:08 AM »

Are those rings in question just glued together? Wonder how many days they last?
We crackled some ruby heating with a torch then spritzing with a spray bottle, worked good because you could get just a little cracking with a tiny amount of water, looks more natural. Some just got one crack, once that is heated with flux it is quite convincing.
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« Reply #11 on: April 20, 2011, 01:16:21 PM »

I've seen those as well Lee, they are quite convincing!

I too have seen lots of faked points! Have a few here right now, lol. From China, sold as natural quartz points, some are natural due to inclusions but the points are most definitely cut & polished into points not natural ones! :/
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« Reply #12 on: April 22, 2011, 11:23:56 PM »

Hi Jamie,
I had to shake my head the other day when I was buying some synthetic corundum and asked the dealer if he had any of the rough. He pulled out a couple of beautiful double terminated crystals that he had fashioned himself but kept quiet. He was very clever to imitate natural surface textures and I was stunned for a minute as I was almost certain the material I was buying was a synthetic even though we had not actually talked about that but these darn things looked pretty natural.
He readily admitted they were by his handicraft and said that perhaps I would find them useful when selling the faceted stones!! I had to laugh and wondered what he must think of me buying synthetic stones.
I made the point that I wanted unaltered rough and he said he would bring some into his shop for next time.`Geez.
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