How does turquoise form

Either way, the backing strengthens the stone and makes it much less likely to break and easier to cut. Without some form of backing, they would otherwise be unusable. Sometimes turquoise will form surrounding and mixed in with angular fragments of broken country rock. This is called turquoise breccia and sometimes makes interesting gems of contrasting turquoise and mother rock, which in many places in Nevada is a black chert.

Since turquoise is a mineral that is deposited by water solutions, turquoise can take the shape of cavities left behind when the stems and parts of fossil plants are dissolved out of the harder host rock. This can also occur where fossil clams leave behind voids when sedimentary rocks host turquoise deposits. This is referred to as "Fossil" Turquoise, and it is very rare.

The other colors that appear in a turquoise gemstone come from the matrix or host stone that the turquoise was formed in. The host rock matrix can be golden, rust-red colored, black, brown or be darker shades of green or blue. In Nevada, a black matrix is usually present from black chert a common host rock ; a yellow to gold to brown shades of matrix form from iron oxide.

Some turquoise matrix is hard and takes a good polish while other forms can be soft and do not polish as well as the turquoise itself. Matrix that is thin and evenly spaced over the surface of the stone is commonly known as a "spider web" matrix.

Spider web matrix usually enhances the collectability and value of turquoise in the US, but in some other places, it makes the stone less valuable. Spider web matrix patterns are fairly common in some Nevada mines.

Turquoise is most commonly set in gold throughout the world, with the exception being the Southwestern US, where is is most commonly set in silver. Because yellow gold forms a quite different background for blue stones than does silver, light blue stones are favored for finer pieces, stones often so pale that they are not wanted by jewelry artists that work in silver.

Most Persian Turquoise, offered at very high prices, is pale and almost always set in gold. Today, only one mine at Apache Canyon in California works at a business capability. The turquoise happens in the form of vein or seam fillings and as compact nuggets, most of which are tiny in number. Currently Arizona is the most important value producer of turquoise.

There are several mines in the state, two of which are renowned for their distinctive color and performance and regarded the finest in the sector: in August , the Sleeping Beauty Mine in Globe stopped turquoise mining. Due to the increasing world market price of copper, the mine chose to ship all the ore to the crusher and focus on copper manufacturing. The cost of untreated natural sleeping beauty turquoise has increased dramatically since the closure of the mine.

As of , the Kingman Mine is still operating outside the town alongside a copper mine. Other mines include the Blue Bird mine, Castle Dome, and Ithaca Peak, but are largely inactive owing to elevated operating costs and federal laws. Morenci and Turkey Peak are either idle or exhausted. Nevada is the other major producer of the country, with more than mines producing large amounts of turquoise.

Unlike elsewhere in the US, most of the Nevada mines were mainly used for their turquoise gem and very little was retrieved as a by-product of other mining activities.

Nevada turquoise is discovered as nuggets, fracture fillings and interstices between pieces are discovered in breccias as the cement coating.

A majority of the material produced is hard and dense because of the geology of the deposits of Nevada, being of sufficient quality that no treatment or improvement is required. Although almost every state county has yielded some turquoise, the main manufacturers are in the counties of Lander and Esmeralda. Nevada has created a broad variety of colors and combinations of multiple matrix motifs, with Nevada turquoise coming in distinct colors of blue, blue-green, and green. Some of this unusually colored turquoise may involve important zinc and iron, causing the lovely tones of light green to yellow-green.

Some of the colors of blue to green-yellow may effectively be variscite or faustite, which is comparable in shape to turquoise secondary phosphate minerals. This area was regarded by the indigenous Monitu as the Turkey Country. The peninsula has six mines, all on its southwest shore, spanning an area of approximately km2 sq mi. From a historical view, the two most significant of these mines are Serabit el-Khadim and Wadi Maghareh, one of the earliest recognized mines.

The former mine is about 4 kilometers from an old temple devoted to the Hathor deity. The turquoise is discovered in basalt-covered sandstone, or was initially overlain. Most of the turquoise mines throughout the southwest are all mined out with the exception of Nevada and a few in Arizona. Nevada has been the leading producer for American turquoise for some time.

Turquoise is primarily made up of copper, so it's not a big surprise to find there are also a lot of copper mines in both Arizona and Nevada. The combination of arid climates and copper rich regions make these places hot spots for good quality turquoise.

Tanner Sr. The duo are at the helm of Gallup, New Mexico's Tanner's Indian Arts , a family-run store that's been in business for over 60 years. Turquoise can be as soft as chalk or as hard as a 6 or 7 on MOH's scale — the harder and more intense colors tend to be more valuable. Another variable in valuing turquoise is comparing all-natural turquoise to 'stabilized' or 'enhanced' turquoise. Turquoise is generally a naturally soft, porous stone that sustains damage in the cutting process — only the truly rare, good stuff can be cut and shaped for jewelry without any kind of enhancement first.

A 'stabilized' stone means soft, low-grade turquoise has gone through a special process that enhances its color and hardness. The process involves putting the stone under pressure so that it absorbs a type of clear filler, either made of epoxy or plastic. The result: a harder stone that can actually be manipulated and cut, but because it required all that help, it's not super valuable.

There are other types of cheap turquoise that you may have spotted in gift shops. Reconstituted or chalk turquoise is made up of fragments of stones that are crushed into a powder and mixed with epoxy. This results in harder blocks that can then be cut into slabs or stone shapes. Then there's the fake stuff: Block or imitation turquoise is usually made of dyed plastic or produced by manipulating another stone like howlite so that it looks like turquoise.

We always encourage anyone looking to purchase turquoise or turquoise jewelry to ask questions about the stones and forever say 'if you don't know your turquoise, know your turquoise dealer. It is indeed a special stone and one to be collected and celebrated. According to Otteson, the grade makes all the difference in determining the stone's overall value.

Like other gemstones, turquoise is graded according to criteria including the 4Cs — color, clarity, cut and carat weight — but it also has other unique factors to consider, like the location of its origin.

As a miner and a cutter, I have quickly learned to never get my hopes up too high when mining, because it's hard to tell how good it is until it's cut. Gem grade turquoise will take your breath away and send your heart rate off the charts. If the Copper content is high, you will see the blue green color of the copper chloride in the acid solution even before it is put into the flame. Nevada Outback Gems. Find out more by checking out All of our links below:. Premium Jewelry, with Gemstones of all types.

Top Quality Loose Gemstones - Gemstones of all types. Rare Crystals and Gemstone Rough, all types. Chris' Gold Prospecting Encyclopedia. Take a virtual tour of our Nevada Turquoise mines. Miners Reference Pages. California Gold Rush Stories. More Info about Turquoise, the Beautiful Gem. Nevada Outback Gems Homepage. Build Your Own Mining Equipment. Investing in Gold and Precious Metals. Basic Placer Mining.