It was mentioned in another thread that “99% of all turquoise is stabilized”, which, for me, has raised the following questions:
What is stabilizing and why is it important?
Is a stone at greater risk of cracking if not stabilized?
Typically, who does the stabilizing - the artist or an outside source?
What is the process?
How can you tell if a stone is stabilized or not?
Are unstabilized (“natural”) stones in older jewelry considered more valuable or desirable?
Is the “99%” referring to just today’s jewelry?
When did stabilizing turquoise start?
Sorry for all of the questions. Hope I’m not the only one who doesn’t know the answers.
I would assume more is stabilized than natural, but I don’t know what the ratio is. Turquoise is a 3-6 on the mohs scale,
" Low quality natural turquoise called chalk can be scratched easily and can have a hardness of around 3. … Stabilizing processes can be used the bring the hardness of low quality turquoise up to a 3.5 or more. Quality natural stones have a hardness between 5 and 6 without any help."
So, you can see there is a big range. I also read that the closer to the surface the harder. That statement makes me imagine that some mature source that has been mined for a long period of time likely could possibly have a lower quality because we have dug down.
Many of the turquoise dealers that we purchase from claim the stone is natural. I don’t know, but artists that inlay the stones and have to cut it can tell by the smell. Most of the time the cutter is who is going to stabilize the stone. You have some different processes.
The process has become more sophisticated, but I think it has been going on for a longtime. I was told a story by an old trader who purchased some stones during the 50s, the next morning when he woke the stones had already started to change color. That seller had apparently soaked the stones in some type of grease.
Here is a informative document discussing one of the treatments of medium to higher grade turquoise stone. I found this interesting and learned somethings about identifying some of the tell tell signs (some pretty obvious lol -laughing because I did not see it). Personally, I think I may have held one or two natural stones in the last year. One was Hubei and knew it like the natural river-rocks when I touched it. In the end I conclude that it’s not that important to me to identify gem-grade natural because it is rare and I’ll probably only know it when I touch it or pick it up from the ground myself : ) In the meantime, there is so much stone made available through treatment to see and wonder at.
I think you have all the information you could ask for now! Lol. I’ll put my two cents in. I feel like I learned a lot about stabilization while on my trip to Arizona. I noticed that a lot of the turquoise I found in the ground was soft enough to break in my hand if I applied enough pressure, and some just crumbled to dust just by picking it up.
I was told that what makes some big name turquoise so expensive and desirable, is not just aways the colors and amazing patterns, It’s the hardness and durability. Some turquoise can be pulled right out of the ground, cut up, and set into jewelry with no stabilization needed. Sometimes, just a simple backing is needed before being set into the jewelry. This is very rare though, and not the case with most turquoise. Most turquoise needs to be stabilized to protect it from breaking or crumbling.
When I talked to the lapidarist, he said that he stabilizes for a few reasons:
To make the stone hard & durable. Turquoise is porous, and when soaked in stabilizing solution, soaks it all up and hardens itself throughout. That way when we wear a turquoise ring and accidentally hit it on a hard surface, it makes the stone less likely to break on impact. Have you ever seen turquoise with natural pyrite inclusions? The lapidarist also told me that the stabilizing solution helps keep the pyrite matrix from falling out in chunks when he cabs up the turquoise.
To protect color. Since turquoise is porous, it absorbs easily. Body oils, sweat, dirt and other outside factors can accidentally be absorbed by turquoise. This is why turquoise can change color over time (we see this more commonly with older turquoise, before stabilization was widely utilized).
To enhance color. Stabilizing brings out the color of turquoise. I was lucky enough to pick out some rough, natural Bisbee, and then the lapidarist stabilized for me. I must say, even though I prefer the color & matrix of the natural Bisbee I picked out, I guess I feel better knowing that it won’t crack in my hand. The lapidarist reminded me that stabilizing enhances the color that the turquoise already has, as opposed to dyeing turquoise, which is meant to intentionally change the color of the stone.
I know I’ve posted these pictures before, but I didn’t really elaborate on the before & after results.
I would agree with Jason that most turquoise set into jewelry is stabilized. Therefore, instead of looking for “natural” turquoise, I think we should look for turquoise that has been stabilized properly. Sometimes, the stabilizing solution is mistaken for quartz matrix. I think that the stabilizing shouldn’t even be noticeable to the untrained eye. On this older necklace (1970’s) that I sold, the stabilizing solution is THICK and I don’t care for it at all. It looks like they dunked each bead into stabilizing solution.
The Heishe strand on the right shows poor stabilization; The stabilizing solution has even turned brown. The Heishe strand on the left however, shows little to no signs of the stabilization process.
So, to summarize:
Pros of stabilizing:
-hardens the stone
-protects the stone from breakage
-prevents color change
Cons:
-can change the stone’s natural color permanently
-poor stabilizing looks like plastic coating. Yuck.
-stabilizing solution can turn yellow/brown over time
Thank you Jason, singingriver, & Bigbree for the detailed information and clear explanation! You have all “stabilized” my curiosity. I didn’t realize that natural turquoise could be so brittle and fragile.
Thanks for this post! I now know why my heishi I just bought but don’t like is the way it is. My stones look like the one on the right. Enough so I did the hot needle test just to rule out fake. I might still post it just to get some feedback.
Thank you Jason and singingriverjewelry., I enjoyed reading the article on Zachery Treated Turquoise. I recently purchased some turquoise from a now retired jeweler who had traded for it back in the 70s in Arizona. He and his brother cut most of the pieces into cabochon. Some had a black substance on the back he said it was for making it into jewelry. The variety of the colors of turquoise makes it a fascinating stone. Once we get through these next few days of storms I will try and get pictures of some of the stones in natural light to post.
I just cut up some stabilized Kingman last night , it has an unmistakeable odor kind of a plastic smell not too unpleasant.
You can also tell by how easily it cuts… most stabilized turquoise is made from chalky stuff which wouldnt be sold otherwise.because of how soft it is.
Stabilized wont take as high a polish as unstabilized , but it will click against your teeth like the good stuff.
i found all reply under this post very informative. ill put in my two cents on this subject. I totally agree with what Bigbree43 said. For reason #2, I think personally I accept that. Real all natural turquoise change color faster than you think. Specially in the lower grade pieces. I had some beautiful light blue turquoise beads turn into greenish blue color within 2-3 months of wearing. the color became deeper and the overall appearance became more transparent. Some people prefer this “aging” effect of the untreated turquoise (lots of Chinese turquoise collectors like that), but not everyone wants to see the color shift. So for this reason, if the artist or whoever made the turquoise piece “sealed” the piece by covering the whole piece with acrylic based polymer or other kind of polymers, and told you what they did, I can understand that.
All the other reasons are simply making the unusable rock usable. Unless they specifically told you so, they are considered as modification of the material. You are not buying actual turquoise but polymer infused turquoise. For something like this, the polymer is not only covering the surface, but also infused into the whole structure. Most of the time, it also carry color so it looks more appearing to the buyer. I mean if you know what are you getting, thats totally fine. we all know not everyone can afford a real Lander Blue, but at least don’t mislead the buyer.
Lastly, I like my turquoise all natural, that why I always keep my gloves on when I handle them. there is always a piece that is too expensive for me, but at least all pieces I collected will stay the same and does not have plastics in/on them.
“Lastly, I like my turquoise all natural, that why I always keep my gloves on when I handle them. there is always a piece that is too expensive for me, but at least all pieces I collected will stay the same and does not have plastics in/on them.”
So, how do you know when turquoise is all natural? Most of my pieces are older (60s-70s) and none of them “look” like the turquoise has plastic in/on them, but after reading how common it is for stones to be stabilized, I now assume they are. Also, most of my stones have a shine, but they look polished, not coated with plastic.
the most reliable way to check if your pieces have polymer on/in them is to use morden analytical tools (FT-IR ATR). For a more home friendly method, you can try to submerge them into water for 1-2 hours ( you might need to submerge overnight for those high quality ones). If you can see a color darkening change after water submerge, your turquoise should be free of polymers.
Will this color change from submerging a natural untreated stone be only temporary?
Also, when did stabilization of turquoise fist appear and become common?
I have recently been reading a lot about this subject. I’ve come to appreciate (as stated above) that stabilization is necessary for the majority of turquoise stones that aren’t as high on the MOHS scale and wouldn’t otherwise be able to withstand the cutting and setting process and hold up to wear. The problem I have with it is that it’s just so hard to tell, and turquoise never seems to be clearly labeled as stabilized. I know I make a habit of asking about it when I look at turquoise jewelry in stores, and I’m almost always told the piece I’m looking at is natural untreated turquoise. That just doesn’t seem consistent with what I’ve read, which is that the vast majority of turquoise on the market is treated. So the whole process just feels very shady.
the color change is temporary but could last a few days depends on how humid the environment.
As for turquoise mining business, of course they want to use stabilization process. You have listed all the benefits but don’t you think all the benefits are for them to make more money? I agree very few material from the mine are good enough to use without stabilization, but is that exactly the reson why turquoise is a kind of soft gemstone?
From my experience, you do get great material ( hard, intense color) directly from the mine, so that is something we as collector wants to collect. I also understand not everyone can afford this, so stabilized version has its place, but PLEASE stated the stone has been stabilized when you sell or exchange a stabilized piece.
So, how do you (personally) know if the turquoise is all natural without using an analytical tool or the water method before you purchase a piece of jewelry? Are you mostly relying on the word of the seller?
I personally only buy raw materials from the mine so I know it is all natural, but if I have to ID a piece, I’ll ask the seller to submerge it in water for a while and most of the time you can tell within 20 mins.
As I mentioned before, for some really high quality material, you might need more time in water before you can see the changes and that when analytical instrument comes into play. For something that fancy, you don’t mind to pay an extra 50 dollars or so to ensure the quality of the stone.
This actually answers a lot of questions concerning the stock of turquoise rough I had from my dad. All of the pieces I have been working on, so far, have shown just such a color change when they have been wet for a while.
In fact, in China, people will keep their turquoise stock in water before use. It will make the material more beautiful and prevent cracks for some really high quality ones. (Top quality material is harder and also easier to form cracks when it is really dry)
I didn’t realize that natural turquoise could be so brittle and fragile.