Any turquoise nerds out there?

[ts44]

My sister looooves turquoise and is enamored of the examples with strong matrix and unusual colors. She can't afford to indulge herself very often and I want to get her a gift that she can make into a statement necklace. I found two giant turquoise beads online that seems to fit the bill but know next to nothing about turquoise and want to get your opinions.

I would assume that there has at least been a paraffin wax treatment done as I understand this is usual for turquoise to stabilize the color? I have contacted the lister for provenance but I'm going to also assume that it will likely be unknown.

Here is Bead #1:

 

[ts44]

Another view of #1:

 

[ts44]

Whooops too small, let me try again:

 

[ts44]

If any other turquoise lovers out there can weigh in on either of these stones I would appreciate it. Any guesses to provenance or treatment? Think they're worthwhile?

Here is Bead #2:

 

[ts44]

Another view of #2:

 

[ma re]

Well, not much to say except that you should get her what she loves. If you ask us if these are the finest of the crop, the answer is probably no (to put it nicely), as the most valuable of turquoise is that of a uniform blue color, with no matrix showing. But when it comes to gemstones it''s a consumer''s choice that matters, as well as personal taste. What''s important is that she''ll love it, regardless of what market says about those pieces. To me, those are some really fun-looking stones, great as beads, or educational pieces to begin one''s journey into the world of gems

P. S. Those treatments are a standard procedure when it comes to turquoise. Dyes are another matter, but I''d say these are not dyed since color isn''t very uniformed.

 

[chrono]

Buying gemstones can be subjective to a certain degree. I would make absolutely sure that she like the colour you have selected. Both are not particularly fine and I don't know if you noticed the fine lines running across the "face" of both cabochons. I doubt these are dyed based on the matrix.

 

[chrono]

This piece is rather unusual so I''m not sure if it''s something she might like:
http://www.thegemtrader.com/Sep%2009%20DTurq%20Page.htm

 

[rustyshrapnel]

Ma Re:

While you may be correct in saying that valuable forms of turquoise are pure blue with next to no matrix, it is by no means the unequivocable "best" form of turquoise. Low-matrix "pure blue" is characteristic of Persian turquoise, traditionally held to be the standard of turquoise, until about the late 1800''s when American turquoise began to be mined. American mines began and still do produce some of the finest-grade turquoise in in the world, and much of their value comes from their unique matrices as much as their varied colors. For example, the "Orvil Jack" green turquoise that was mined from the Blue Ridge mine in the 1980''s retails more per-carat than most of the fine "true blue" turquoise out there due to its rarity and color. Same with Carico Lake turquoise or Damale turquoise, both known for their striking green colors. A true white turquoise with black matrix called "White Buffalo" that only comes from the Dry Creek Mine (be wary of it from anywhere else, they are most likely howlite being passed off as white buffalo turquoise) is also highly prized and valued by collectors. The most expensive per-carat turquoise available today isn''t "pure blue," either; it''s a heavily spiderwebbed-matrix turquoise from the now-defunct Lander Blue mine in Nevada. Morenci mine turquoise is prized both for its beautiful blue hue and its matrix, which is a black pyrite that appears silvery. Ithaca Peak turquoise is highly sought-after (and very expensive) because of several factors: its scarcity, its high-grade natural quality, and its tendency to have a golden pyrite matrix that looks utterly spectacular next to the blue of the turquoise. King''s Manassa turquoise, also prized by collectors, has a unique rhyolitic matrix that appears dusky-golden in nature.

One of the few still-producing high-volume turquoise mines in the US is the Sleeping Beauty mine, whose turquoise is of the low-matrix high-blue variety. Their product is also very expensive in its high-grade natural form, but only about 4% of their monthly haul is good enough to qualify. The rest is enhanced or treated in some way and usually sold off to distributors overseas.

That''s not to pooh-pooh Persian turquoise though! Natural Persian turquoise is absolutely stunning, and still very popular. There''s a reason it was considered the gold standard of turquoise for so long. It''s spectacular.

The quality and grading of turquoise actually has very little to do with presence or absence of matrix. The most critical factor is hardness/density of the stone. Turquoise is a naturally soft (only about 5-7 on the Mohs) and porous stone that can be brittle to work with; very hard high density turquoise will have a nice heft and feel, it will not appear chalky or feel light. A good way to field-test quality on rough turquoise is to lick it! If the stone draws a lot of moisture from your tongue then it''s more porous and not as high-quality. Naturally hard, dense turquoise that''s able to be worked from its natural state (ie, unstabilized or untreated) is extremely rare and very valuable. The second factor is luster. High-quality turquoise seems to glow from within. It has an internal luster that cannot be faked by a nice surface treatment. Low-quality "chalk" or "block" turquoise has a matte, flat, lifeless look to it, even after polish. The next quality criteria are color and matrix, and this is a BIG gray area. Matrix quality is not defined by presence or absence; the only designation is that if there is a matrix, that it be in a "pleasing pattern." This is entirely subjective, but includes things like the ratio of turquoise to matrix, how the matrix is arranged in relation to the turquoise, and whether or not the final product is cut to show off both the characteristics of the turquoise and the matrix to its utmost. Color is even more subjective. For the longest time blue was considered to be the superior color, as lower-grade untreated turquoise does begin to take on a greenish hue over time (we''re talking decades), due to atmospheric interactions as well as contact with body oils and other chemicals. However, many naturally-occuring green-hued turquoise (such as the ones I mentioned above) meet all of the more important quality standards and as such color is now considered only in the question "does it meet the characteristic color of the type locality?" This becomes even stickier because several mines produced high-quality blue and green (in the same stone sometimes!) turquoise, such as the Sky Mountain mine in China and Royston mines in Nevada.

The final quality designation is rarity, which is more of a sub-designation in that it doesn''t technically have to be met for a stone to be considered of the highest quality in the physical sense. However, a stone from a dead or low-producing mine will naturally be considered more valuable to a collector of turquoise than a stone from a high-volume or still-producing mine. Stones with pedigrees are pricier!

In the case of these stones, provided they are genuine turquoise, I would say they have most likely been treated with some sort of stabilization process, which is very common and does not lessen the value of the stone at all if done properly and without any color enhancement. I agree with Ma Re in that due to the variations in the hue of the turquoise that they do not appear to be "color-shot." Because no provenance is given, they cannot be considered "rare" but that has nothing to do with the overall quality of the stone. I would rate these as mine-run, average to good quality turquoise, with the second one being a higher-quality than the first.

Chrono, that Damele you posted is very pretty! That''s an excellent example of the spiderweb matrix I was talking about earlier, and so characteristic of the lovely green Damele hue.

 

[Fly Girl]

I used to be really into tourquoise, and rusty is correct. You begin to collect "name" turquoise that appeals to you. Neither of those beads do it for me. I''d check with your sister to see if she has been hankering for a piece from a particular mine.

Here is my King''s Manassa cuff. One of the larger stones that I own at 1 1/2 inches long.

 

[Richard M.]

Excellent post RS! I was choking on my iced coffee a little up to the time I read it. You know your turquoise!

I know a bit about it also, having cut a great deal over time. When it comes to fine matrix stones it''s hard to beat Lander Blue or Number Eight.

As you point out the sheer variety of colors and matrix patterns are an essential element of turquoise knowledge and appreciation. It''s very wrong to generalize. Consider that Persian turquoise is highly prized for both its "pure" no-matrix blues and for the wonderful matrix patterns also produced there.

I''m also very fond of associated gem minerals like the fine webbed variscites found in Utah and Nevada per the attached image. They lack copper so never occur in blue. They are greatly under-appreciated.

 

[rustyshrapnel]

Thanks Richard! I''m a geology major and fell in love with turquoise during my undergrad days. My personal favorite is Ithaca Peak turquoise. I think the pyrite/quartz matrix they exhibit is simply outstanding. I too enjoy the secondary stones such as variscite; I agree that fine specimens from some of the American mines are every bit as nice as their diva turquoise cousins. I also feel bad for poor howlite, it never gets any respect! It''s always either being passed off as White Buffalo turquoise or dunked in Ty-D-Bowl and heaven knows what else and sold as turquoise. I saw some "colored turquoise" nuggets being sold on e-bay a few days ago that were traffic-cone orange and so clearly dyed howlite that it was embarassing.

Fly Girl, that is a great cuff! The silverwork sets off the stone nicely and that Manassa cab is a monster! Definitely a lovely heirloom piece.

SD Lady, if you''re looking for some high-end turquoise drops, try reputable sites that deal with the raw product like American Turquoise Company and Nevada Turquoise or who work directly with Native American artisans like Twin Rocks. Regardless of where you go, the dealer should be able to tell you whether the stone has had treatment. True turquoise wonks understand there''s no shame in stabilization, so don''t be afraid to ask if that''s important to you. Remember, a stabilized stone will retain its initial color much more readily than an untreated stone, which tend to acquire a sort of patina of age as the decades go by. This is not always the case however; I''ve seen some untreated turquoise from Egyptian tombs that have retained their initial color just as well as any stabilized stone, but that usually only happens in the highest-quality gem-grade turquoise. Also when looking at cabochons, you may see references to cabs being "backed." This is a term used to describe when the back of the cab has been coated with a resin, partly for stabilization and partly to even out the back so it sits more properly in a setting. This is extremely common and not generally a cause of concern, but again if you''re a purist (or you''re looking for something that''s going to look as nice on the bottom as it does on the top) it''s something to inquire about.

If the classic sky-blue turquoise is what you love, Sleeping Beauty mine runs its own retail site. It''s the only mine I know of that lets you shop and buy directly from them with no middleman and you know you''re getting the straight product there.

 

[Richard M.]

Date: 9/28/2009 11:54:49 PM
Author: rustyshrapnel
Also when looking at cabochons, you may see references to cabs being ''backed.'' This is a term used to describe when the back of the cab has been coated with a resin, partly for stabilization and partly to even out the back so it sits more properly in a setting. This is extremely common and not generally a cause of concern, but again if you''re a purist (or you''re looking for something that''s going to look as nice on the bottom as it does on the top) it''s something to inquire about.

Just a comment on ''backed'' turquoise. Some of the very finest, hardest, most dense, durable and desirable turquoise occurs in thin veins. This is often called "saw rock," meaning that the rock around the turquoise must be cut away with a diamond saw to ''liberate'' it. This often results in stones that are too thin to be cut as-is, so they are backed in various ways to make them wearable in jewelry. As RS says, this is often not a bad thing.

I recall some Battle Mountain vein turquoise I once cut. It was amazingly hard and rang like agate against the grinding wheel. It required backing but is some of the best turquoise I''ve ever worked. It will never discolor from skin oils and other contaminants. That doesn''t mean that all ''backed'' turquoise is of that quality but consumers shouldn''t reject all backed stones arbitrarily.

Richard M. (Rick Martin)

 

[pwendyp]

I just glanced at this thread, but this is for SDL...

I know nothing about turquoise, but saw these on Etsy a couple of weeks ago, when searching for cabochons and briolettes. They are expensive, or no? The colour though, is beautiful.

=tags&includes[]=title:2o8h065d]RobinsEggBlue

 

[rustyshrapnel]

Richard, thanks for that backing clarification! I''ve never cut turquoise myself and did not know that about the high-grade pieces. I have noticed several high-grade samples that have been backed and wondered why, though, so I''m thankful for the enlightenment on that.

Pwendy: the price is pretty accurate for 2 flawlessly-matched giant briolettes like that. The seller has other turquoise pieces too, and nothing else they''re offering looks out of order either so they seem reputable. I am not sure where they''re getting that the SB mine has almost stopped producing; to my knowledge it''s the highest-producing mine in the world at the moment. I will say that the amount of really high-quality turquoise has tailed off a bit, though, so when they mention that this is old stock from 10 years ago I''m inclined to believe them.

 

[pwendyp]

Date: 9/29/2009 3:24:23 PM
Author: rustyshrapnel
Pwendy: the price is pretty accurate for 2 flawlessly-matched giant briolettes like that. The seller has other turquoise pieces too, and nothing else they're offering looks out of order either so they seem reputable. I am not sure where they're getting that the SB mine has almost stopped producing; to my knowledge it's the highest-producing mine in the world at the moment. I will say that the amount of really high-quality turquoise has tailed off a bit, though, so when they mention that this is old stock from 10 years ago I'm inclined to believe them.

Thank you for clarifying the pricing, not that I'm going to be buying them! I just thought they were beautiful enough to show here, and a large example, of what I thought was good turquoise. I felt his pricing might be about right, and when I read also, about them being 10 year old stock, it lent more credence to them.

I love the Robins Egg blue - so soft looking. Not sure about earrings for them though, slightly weighty perhaps? Perhaps a double pendant, two length drops...hmmm - nice with yellow metal.

 

[rustyshrapnel]

Well, they''re certainly expensive, but they''re also highly unusual in their size and matching. That drives the price up considerably. Perhaps not even *that* much though; they are VERY expensive. I see those types of prices in finished jewelry from well-regarded Native American artisans, but I''ve also never seen said artisans using ginormous matched briolettes!

Most Sleeping Beauty turquoise is much more affordable. For example, you could get these drops, which are smaller and perhaps more realistic for earrings. I think the faceting on them is pretty too. They''re not near as amazing as those eggs you posted, but they''re quite respectable. The per-carat pricing on these is about right I think; most of the good turquoise I see ranges around 2-8 dollars per carat, with Sleeping Beauty on the 2-4 range. Really nice collectors turquoise can go $10-20 per carat well up into $40 and I''ve seen some Bisbee sold at $80 per carat; but the most expensive I''ve ever seen is a series of Lander Blue cabochons at $180-220 per carat.

I know it''s kind of ho-hum compared to some of the per-carat prices on the rest of the blingers and sparklies flying around these forums, but for turquoise that''s unbelievable!

 

[ger100]

Hi,

I was given what is supposed to be a turquoise bracelet (cabs), in white gold (18K) with SI diamonds. I put my tongue to the stones and they feel like cold stones, i.e., not sticking. They are a beautiful sky blue, shiney; on a couple I can just barely see a bit of white mixed in.

If they are coated, how can one tell that they are indeed turquoise and not just glass or something else? without taking them out of the setting?
Thanks
Ger

 

[rustyshrapnel]

Ger: I commend you for being hardcore enough to lick the stones (as a geo major I've licked a lot of rock and eaten a lot of dirt in my day) but the "tongue-test" really only applies to rough turquoise. Most likely your stones have been stabilized, but as I said this is NOT something to be concerned about. Stabilization is an accepted and oftentimes required process in turquoise jewelry and does not lessen the value of the stones. Are they color-enhanced? That I cannot tell you.

Now, on the subject of your stones potentially being false, I'd be inclined to say they're real given the rest of the bracelet's materials. Why bother putting fake turquoise beads in a nice white gold and diamond bracelet? If you do want to test however, there is a method where you heat a needle and touch the tip to a part of the turquoise. If the pin leaves a mark and there may be thin smoke or a smell, then it is fake. In the immortal words of a fellow rockhound: "Turquoise doesn't burn." Of course if the stones are dyed howlite or some other mineral, the pin test will not work. Short of actually grinding up one of the stones and running tests on it, I can't really come up with any other ways to prove those are turquoise. There are few non-destructive ways to effectively test turquoise, unfortunately.

Edit: Just thought of one! If you can get your hands on a Chelsea filter, dyed howlite will appear reddish and variscite will appear pinkish, while natural turquoise will appear green. However, synthetic turquoise or reconstituted turquoise will also appear green, so it's not 100%, but it would be something you could do without removing the stones from the setting. Also if you have a 30-50x magnification lens, you can see tiny bubbles in glass that wouldn't be there in real turquoise.

 

[ger100]

Thanks rusty.

What got me going (other than the fortuitous discussion about turquoise): the metal is marked 14K, but tests out to be 18K (in several places). I looped the diamonds and they''re pretty much on target.

The blue stones pass the pin test, and they are green under Chelsea. Have not gotten to the 40x test...yet. x fingers

Yes, I agree that given the setting, the blue stones should be genuine and of a similar quality...but ya never know. Too much Antiques Road Show of "replacing" things makes one suspicious. I wish there were a really good way to ID the origin of these stones, although apparently that is not realistic.


THANKS so much for a quick reply. I''ve never had such pretty blue stones before, and will really enjoy wearing the bracelet, especially now that I feel a bit more confident that it probably is what it''s supposed to be.

Ger

 

[innerkitten]

Nice beads. I guess I''m kind of a turquoise nerd. I''m very interested in all the different mines etc. It''s a fun gem and very beautiful.

 

[innerkitten]

I like those eggs a lot but they are pricey. I haven''t heard that the sleeping beauty mine has stopped producing or anything like that though. This web site say''s it''s the worlds largest producing mine. http://www.sbturquoise.com/

 

[innerkitten]

Date: 9/28/2009 2:42:22 PM
Author: Chrono
This piece is rather unusual so I''m not sure if it''s something she might like:

http://www.thegemtrader.com/Sep%2009%20DTurq%20Page.htm

That is an interesting stone. I like the light spot in the center. I love the stuff from Carico lake a lot. It sometimes comes in really beautiful shades of green. http://nevadagem.com/pages/categorypages/carico.html

 

[MonkeyPie]

Fun thread. I live in Land of Turquoise (New Mexico - native americans local here all use it in their jewelery), so I have seen quite a bit. My mom has a Squash Blossom that is downright humongous, and the stones in it are gorgeous. I will admit though, my favorite part of turquoise is how it ages over time. Wearing a piece without the paraffin means that over the years, the oils from your skin will change it''s color. My mom has a watch band she''s worn for longer than I have been alive, and while the stones all started out that pretty, even Robin''s egg blue, they are now every shade of blue/green you can imagine. There will never be another band like it and I love that it''s one of a kind now.