Sunday, May 20, 2012

Turquoise, At Last- December

Gigantic Turquoise Nugget with Indian motif carved on one side ...
 
...and Cowboys on the other.  Image via Tucson Gem & Mineral Exhibition




Persian-style carved turquoise and diamond bandeau. Image via Marie Poutine


Natural turquoise nuggets. Image via Sleeping Beauty Mine
 
 

Image via Cool Spotters


So here we are, at the end of our birthday gem tour. What better gem to finish up than with December's turquoise, a stone with which most of us are familiar. As mentioned previously, in November's topaz post, blue topaz is often considered to be the birthstone for December. However, since most months have alternative birthstones, I went ahead and lumped all the topazes together in November so that we would have something new to explore for December. One of my sisters has a December birthday and she prefers turquoise so I actually never knew blue topaz was an alternative.



Image from Wager Copenhagen Jewelry.



Most of us here in the United States automatically think of the Southwest and American Indians when we think of turquoise. However, the word turquoise, which dates to the 16th century, comes from the Old French word "Turquie" for "Turkish" because the mineral was first brought to Europe by Levantine traders, or "Turks". These stones most likely originated in Iran or Egypt, where the finest turquoise was mined until recently. It is one of the oldest know gemstones used in jewelry and has been the most valuable non-transparent mineral used in jewelry-making. There is evidence that some surface mines in Persia were mined as far back as 2100 BC while yet more evidence shows that turquoise was used as far back as 6,000BC. The oldest known piece of jewelry, a turquoise bracelet, was found on the wrist of a 7000 year-old mummified Egyptian queen, though shells and beads with holes probably for stringing have been dated as much older. While December's stone was worn and highly treasured by the ancient Persians and Egyptians, Europe was not introduced to this beautiful stone until the time of the Crusades. Turquoise has been extensively used since about 200 BC by both southwestern U.S. Native Americans and by many of the Indian tribes in Mexico. "Indian style" jewelry with turquoise mounted in or with silver is relatively new. Some believe this style of Jewelry was unknown prior to about 1880, when a white trader persuaded a Navajo craftsman to make turquoise and silver jewelry using coin silver. Prior to this time, the Native Americans had made solid turquoise beads, carvings, and inlaid mosaics.



Leekya Deyuse Zuni carved leaf. Image via Art of the Zuni at Ohio University


For centuries, "Persian turquoise" indicated the very finest turquoise available, mined in Iran for centuries. This began to change, however, in the early 1800's when deposits of turquoise were discovered (or rather re-discovered) in the southwestern US. The oldest mine of any kind on the North American continent, the Cerrillos turquoise mine just south of Santa Fe, New Mexico, dates back at least 2000 years. Today, Persian turquoise generally indicates a clear robin egg blue stone without black or other veining.

20-karat yellow gold ring with a oval smooth turquoise cabochon. $1,750, tax excluded.
Via Daniel Gibbons Jewelry
 


So, what is turquoise, besides a drop-dead, catch-your-breath shade of blue? Well, it is hydrated copper aluminum phosphate. It is sometimes collected as a by-product of copper mining. Turquoise occurs in a range of drop-dead catch-your-breath hues from grey-blue to powder blue to sky blue, and from a blue-green to a yellowish green, even to brownish and lime shades. The blue color comes from copper (Arizona turquoise) while the green tones (Nevada turquoise) may come from iron impurities (which have replaced the copper) or dehydration. Heated stones will actually turn to more green-ish hues. Yellow-green shades form when zinc is present and is a rare color of turquoise found only in a few mines. Colorado and New Mexico have both blue and green Turquoise, however, most Turquoise in America is found in Arizona and Nevada. Turquoise is also mined in Northern Iran, Pakistan, Mexico, Israel and China. The highest quality Turquoise, however, that of sky blue is usually found in Northern Iran and sometimes in the Southwest of America.




Antique Pearl Turquoise And Diamond Necklace
Victorian Pearl, Turquoise, and Diamond Necklace.
17,850 GBP/28, 689 USD
Image via George Pragnell


So, turquoise is a hydrated copper aluminum phosphate? OK, what does that mean? The best way to explain is to share the process with you from The Turquoise Guide:

"Turquoise is not a primary element like iron, copper, silver, etc. Rather, it is a secondary element formed over time as a result of minerals that accumulate in the planet's crust through two processes, weathering and oxidation. Turquoise usually occurs as encrustation in cracks or as nuggets. As water moves through porous rock, minerals are dissolved, such as copper, aluminum and iron. Often these minerals come from other secondary elements; copper might come from azurite, for example. Over eons of time, these minerals accumulate in pores, cracks and crevices to form deposits of the material we know as "turquoise." Oxidation of other minerals present at the site contribute to turquoise formation. The color of the stone can vary depending on the amount of iron and other minerals present. Since turquoise forms in other rocks, it is often veined with other minerals to create a beautiful matrix.

Most turquoise forms in drier climate, and often in rock formations that originated from volcanic activity; such formations are conducive to turquoise because they have high levels of iron oxides.

The process of formation can differ from region to region, and even from different locations in the same region, leading to unique turquoise appearances. For this reason, turquoise is often named after the mine from which it came. An example is "Sleeping Beauty Turquoise," which comes from the sleeping beauty mine near Globe, Arizona." Source







Turquoise is an opaque, porous stone, which is why it is usually sealed with wax or epoxy. It is soft, rating a 6 on the Mohs scale (just a bit harder than window glass), and has a waxy luster. Turquoise is classified as a cryptocrystalline mineral.  This means that the crystals that form it are so small that they are difficult to discern without the aid of a microscope. Usually ...


1.7 x 1.3 x 0.8 cm. Superlative, sparkly, best color, sky-blue turquoise microcrystals richly cover matrix on this stunning thumbnail specimen from the locality with the best turquoise crystals in the world - the Bishop Mine at Lynch Station, Virginia. Discrete, well-formed turquoise crystals are very rare in nature. Classic for the old locality, and seldom seen today. Ex. Irv Brown Collection.
Image and text via irocks.com



There are other surprises ...


This incredibly well-preserved 2.2 cm jaw of a fossil mammal from the Pleistocene is now writ in turquoise. These trickle out of the desert from time to time, found in handfuls by the lucky prospector. What happened is that copper-rich solutions flowing through the fossil beds, from nearby copper deposits, altered the bone, or the fossilized bone, to turquoise. These replacements are generally complete all the way through, and are invaluable to researchers as they preserve superb bone detail internally as well as externally. This is one of the finer examples I have seen because it has a complete lower jaw (of a marmot-like rodent, I am told), and the aesthetics are good.
Image and text via irocks.com
 


The matrix, or veining, of turquoise is the remnants of the host rock where the turquoise formed. In some regions such markings are considered to be beautiful, such as in the U.S. Southwest and the Far East. In other areas, such as the Middle East, these markings are thought of as imperfections and the stones that carry them are valued less. The matrix can be different colors, base on the host, or "mother" rock, with black (from iron pyrite or iron sulfide) being the most favored as it gives a nice, high contrast to the stone. Yellow matrix is often rhyolite, an igneous, volcanic rock.  Since turquoise usually forms in rock with a volcanic origin, the presence of rhyolite should not be surprising. Brown matrix usually consists of an iron oxide, of which there are sixteen different types. The best known of the iron oxides is probably hematite.




Image via Cowboys & Indians



Let's take a minute to talk about something that some of us will find controversial. White turquoise has recently appeared on the market as a "rare" variety of turquoise. There are also Sacred Buffalo and White Buffalo Turquoise stones and jewelry available. I have read a good bit on this variety of turquoise, both in support of and in opposition to the validity of claims about whether or not white turquoise is authentic turquoise. It's very confusing but let's see if we can sort it all out. There is no arguement from me that stones being sold as white turquoise, no matter the name, are beautiful.


Durango Silver Company

Those who hold white turquoise to be authentic explain the stone as having formed under the same conditions and processes by which turquoise is formed but that the environment did not include copper or iron, which give turquoise its blue and green hues, respectively. The most widely quoted source describing the discovery of white buffalo turquoise is found on page seven of the January 2002 Miami Valley Mineral and Gem Club newsletter. However, be aware that there are several names for this stone floating around. Here's what I've found:
  • White turquoise- turquoise formed without copper or iron. This seems, to my understanding, to be sort of generic term and is usually actually howlite or some other white stone containing matrix.
  • White Buffalo Stone- formed from the minerals calcite and iron but since it has no copper, it is tecnhincally not turquoise. It should not be marketed as "white turquoise" any more than the howlite or magnesite that are sometimes passed off as white turquoise. Sometimes called "Sacred White Buffalo."
  • Sacred Buffalo Turquoise- Sometimes called Dry Creek Turquoise. Found in one mine in Nevada in 1993, this stone in fact assays as turquoise. Generally of a paler blue, sometimes almost white, there is little consistency in the color of stone from this particular vein. Derives its name after the belief by local Indians of the sacredness of the rare white buffalo.


Sacred Buffalo (Dry Creek) Turquoise
Image via Ruby Lane

So confusing, right? And the confusion is thickend by people misusing the names, such as White Buffalo Turquoise, Sacred White Turquoise, and so forth. As a counterpoint, Mindat.org, an online mineral and locality database, states emphatically that if it's not white, it's not turquoise. The Gem Society also states there is no such thing as white turquoise. Finally, the New Mexico Bureau of Mines and Mineral Resources describes turquoise, in its publication "Non-Metallic Minerals Mineral Resources and Their Economic Features", as having a color ranging from sky-blue to apple-green. No mention is made of white.



So- that's the debate. I know what I believe and I'll let you decide for yourself.


Yadda Yadda Yadda-- but what about the mystique? Oh baby...


Turquoise is considered a sacred stone for the North American Indians as well as the Tibetans while in ancient Persian, the sky-blue gemstones were originally worn around the neck or on the hand as protection to ward off unnatural death. The American Indians believed that the celestial blue of this stone was stolen from the heavens by storms, and that if one went to the end of the rainbow and searched the damp earth, he would find a turquoise. Many Indian cultures still hold that turquoise provides a connecting between the sky and the lakes. Persians believed that if a person saw the reflection of the new moon in a turquoise stone, they would soon encounter great luck. FYI- we call the new moon the phase when the moon is invisible to earth but the original meaning was the appearance of the first visible sliver of crescent moon after the moon was invisible. Hebrew tradition holds that Issac, son of Abraham, opened the first Persian turquoise mines.




Mosaic mask and close-up detail. Images via Mexicolore



Considered a holy stone by many cultures,  turquoise was often used by shamans in rituals and ceremonies,  to promote mental and spiritual clarity and expansion as well as to enhance wisdom, trust , kindness and understanding. The ancient Aztecs in Peru used to decorate their ceremonial and death masks using turquoise and King Tut's burial mask contains inlaid turquoise. It was believed that if the stone changed color, imminent danger was approaching. Turquoise will, in fact change color, but this is normally due to heat, dust, light, or even the ph-value of the wearer. The Zuni also believed that the stone would protect from falling, especially from falling from a horse and that it made the horse more sure footed.



TWO CHINESE CARVED TURQUOISE SNUFF BOTTLES,
Two Chinese carved snuff bottles. Image via Christie's



Turquoise is said to attract money, success and love. Its alleged powers include protection, healing, courage, friendship, and luck as well as relaxing the mind and easing mental tension. Its bright color is supposed to eal the problems caused by a depressed outlook and to give self-confidence to those who feel they are lacking.


Native American Indian Snake Fetish
Zuni rattlesnake fetish. Image via Horsekeeping



 A gift of Turquoise represents friendship and luck. Turquoise was often carved into the shape of animals and birds. These carvings were placed in Indian tombs to attract beneficial spirits and to guard the dead. Turquoise was also used by medicine men for healing and by warriors who fixed turquoise to the end of their bows to insure accurate shots. It could also prevent blindness or cure everything from stomach aches to psychiatric disorders. It could provide a good rainfall, prevent danger, influence dreams, and predict the weather. In  Mexico, turquoise could not be worn by mortals. In Tibet, turquoise remains the most popular material used for adornment and is important in religious ceremonies.



Bisbee Turquoise Nugget. Image via Durango Silver Company



So you want to buy some turquoise? The number one thing I feel you need to keep in mind is that all turquoise is not equal. Along with that, all turquoise is not actually turquoise. Just because it's turquoise blue doesn't mean it's turquoise stone. Our December stone is painfully easy to fake, from plastics and resins to dyed howlite or other minerals. The best thing to do is, of course, buy from a reputable dealer. Ask the dealer if the turquoise is natural. Stone density is the most important characteristic of turquoise. Lower grades of turquoise are too soft to be worked and too porous to be worn, but they can be stabilized with a resin under high pressure to provide strength and deeper color. Almost all of the turquoise for sale across the country is stabilized. If you ask, "is it stabilized," the seller is required to tell you. Higher grades, more dense and harder, don't have to be stabilized and are sold as natural turquoise. Similarly, if you ask: "Is it natural?" and it isn't, the seller has to tell you that the stone is not natural turquoise. Turquoise chips, too small to be worked or the cast offs of the grinding process, can be reconstituted into a hardened block that is cut into "stones." This turquoise can also be dyed, oiled, or waxed to deepen its color. This is called block turquoise and is the lowest quality of "real" turquoise. It can not legally be passed off as stabilized or as natural turquoise. All of it is, in a sense, real turquoise. And it can be quite lovely. You just shouldn't pay premium prices for stabilized stones, or for reconstituted turquoise.

Stephen Dweck Carved Turquoise & Bronze Ring sz 7
Carver Turquoise and Bronze ring by Steohen Dweck. Image via Portero



The Collector's Guide lists five types of turquoise as described by law:

Natural turquoise - turquoise that is so hard and beautiful that it is simply mined, cut, polished and set into a piece of jewelry or carved into a fetish or sculpture. Less than 3% of all the turquoise on the market worldwide is natural.

Stabilized turquoise - soft or "chalk" turquoise has been infused with a clear epoxy resin. The resin, under pressure, absorbs into the rock, which permanently hardens the rock and deepens the color. Unlike the collectible natural turquoise which deepens in color over time by gradually absorbing oils from the skin as it is worn, the colors in stabilized turquoise are permanent. Most of the turquoise on the market is stabilized and should not cost as much as natural. Stabilized turquoise can be very beautiful, and is a good buy.

Treated turquoise - soft or "chalk" turquoise that is stabilized as described above, except that the epoxy resin is also dyed. Colors in treated turquoise have a tendency to look artificial. Prices should be much less than natural or stabilized.

Reconstituted turquoise - turquoise "chalk" that is very low grade and has been ground into powder, saturated with epoxy resin, dyed, and compressed into blocks or cakes to be cut into shapes for jewelry making. Prices should be most inexpensive.

Imitation turquoise - there is no turquoise in this category. Either there are stones like howlite (white stone, very porous) dyed to look like turquoise or there is pure plastic (epoxy resin) that has been dyed to look like turquoise. It is a shame that these materials are set in silver and priced as if they had intrinsic value.


It can get complicated but trust is the bottom line. As I've said with almost every birthstone post, buy from a reputable dealer. You should buy what you like, not necessarily what the market or fashion dictates, but you should know what you are buying.


Tibetan Turquoise Necklace
Tibetan Tribal Necklace. Image via Gemstone Jewelry Advisor


Once you have purchased your sky-blue lovely, you'll need to take care of it. Natural turquoise is soft and fragile (easily scratched, easily broken). Always handle with care. As with most stones, it's best not to wear for gardening, working out, mountain biking, full-contact football, or cleaning. Stones that have been stabilized are a bit tougher but still require a gentle touch. Store you turquoise pieces separately from hard stones or metal jewelry to avoid scratches, even perhaps in a soft pouch. Turquoise is easily damaged by solvents because it is a phosphate mineral. It should be protected from perfumes, skin lotions, hair sprays, sunscreens, and other cosmetics. These can damage the stone's surface polish. Contact with oils in the skin should be avoided as well for the same reason. Because even the hardest turquoise is still a soft stone, dirt can be depositied in the pores of the stone, thus causing color change. These changes, once they occur, cannot be reversed. These precautions are particularly important for natural, unstabilized stones. Over time, exposure to the sun can lead to discoloration and dehydration. Store your natural turquoise jewelry in a dark place. Do not wear it on sun bathing occasions. Most jewelry cleaning solutions should also be avoided. Rather, clean your turquoise with a soft cotton cloth and only the gentlest of elbow grease.


The Turquoise Lady has these tips for keeping your turquoise lovely:

1) Always remove your turquoise rings and bracelets before washing dishes, gardening, painting the walls, automotive repairs or any other household dirty work. Household bleach can radically and permanently affect the color of turquoise.

2) Hand lotion can change the color of a stone. So put on any perfume, lotions, etc. first, then put on your turquoise.

3) Never use an ultrasonic jewelry cleaner on your turquoise.

4) Don't wear turquoise in the swimming pool or hot tub, as the chlorine or bromine used in keeping the pool clean, can dramatically affect its color.

5) Don't wear turquoise in the shower because soaps can affect it.

6) If possible, avoid the use of chemical silver polishes with turquoise jewelry or be very, very careful not to get them on the stone. The acids present in some chemical polishes can change your stone's color as well.



Silver Post USA has a list of some of the more prominent mines in the Southwestern United States. I am going to encourage you to click here to see that information as this post is beginning to become rather lengthy. She has a neat map and a little informational blurb about each mine. Turquoise actually varies in color by the mine from which it came due to the different soil composition above the stones. As water leaches down through the soil, it picks up these various chemicals and minerals, carrying them down to where the turquoise is forming and impacting the color. It is possible to identify the mine from which a stone came based upon its color. Turquoise from The Sleeping Beauty Mine in Arizona, for example, are known for its intense medium blue with little to no matrix. So do click on the link above and check out the incredible varieties of turquoise.


Sleeping Beauty Mine Turquoise. TurquoiseAll.com

The Number 8 mine in Utah, on the other hand, is know for its powder blue turquoise with a spider web matrix of colors ranging from golden brown to black



Number 8 Turquoise. Image via Turquoise Buffalo



Carico Lake Turquoise is a stunning lime green due to a low copper, high zinc composition.
Image via Squidoo



My bracelets that I've had so long I don't even remember where or when I got them.



Top- pin, Middle- screw-post earrings, Bottom- earrings set in gold, a gift from my husband before we were married. I've considered having the round earrings re-set as a necklace each for Zippy and myself.



Falize Brothers, Coronation Crown of Queen Marie of Romania (replica)
Coronation Crown of Queen Marie of Romania, set with turquoise.
This is a 1923 replica which she commissioned as the original, um went missing.
I know, she misplaced a crown.
This is a side view- the chains on either side hang down over the ears.
Image via Maryhill Museum of Art




Tiny turquoise crystals.
Crystals of turquoise rarel exceed 3mm in size but look at that color!
Image via Leonid Surpin


 

Turquoise Sultan Ring
Sultan ring: gold, silver, turquoise. $850
Image via Nersel Irene


So there we have it, at long last: a completed look at our beautiful birthstones. I must admit, this was more than I thought I was getting into but WOW! And we've only looked at the twelve stones assigned to months for birthdays. If you get a chance to go to ANY rock, gem, or mineral show, ANYWHERE --- GO!




Image via Turquoise Feather Jewelry



So now what? Well..... did you know about birth month flowers? Yippee! Just in time for gardening season. So keep an eye on me here in the jungle and we'll be off on more adventures of discovery in the jungle of life. Oh look- a turquoise!



Turquoise and coral pendant. Image via Ruby Lane



2 comments:

  1. I have been waiting for this post!!!

    Turquoise is the stone I wear. The stone I love. All my jewelry is turquoise except for a couple little pieces of my birthstone - emerald (very tiny!)

    You have not disappointed! Another fantastically thorough and informative post illustrated with gorgeous images.

    Thank you so much for completing the series with such a stunning post.

    ReplyDelete
  2. Thank you so much for your great comments and support as we've explored the birthstones. I sort of had you figured for a turquoise gal. Don't forget to check back in as we start looking at birth month flowers. Thanks again.

    ReplyDelete