Are there different colors of turquoise

Intensity is how rich and dark the color is. There is a range of intensity from white to pales to medium to rich. As a rule of thumb, the richer and darker the color the rarer and therefore more valuable it is.

A few exceptions contradict this rule. It is rare to find white turquoise and it is valued more than some of the slightly blue pale variations and there are hues of turquoise that are unique and score highly. When dealing with multiple colors, always go by the lower scoring color found on the stone. Another factor of a color is the consistency of the coloration and transition between colors. In needs to be reinforced that this is just an evaluation of the changing of the color of the turquoise not the turquoise to matrix which is a completely different material.

The natural chemical composition of the host rock turquoise was formed on can influence the way the turquoise color is presented. Sometimes the stabilization process can leave hash ugly scars on the stone. Sharp and harsh color transitions are not as valuable as smoother even turquoise color transitions. When dealing with multiple color transitions, always score by the lower scoring element found on the stone.

This scale shows some example transitions of color, the harshest being on the left and most desirable on the right. This stone displays a beautifully smooth transition between a classic turquoise sky blue and a richer darker green. When grading for color, always go by the lower scoring elements found on the stone. Because the blue is less rich than the green it is to be used as the measuring color.

This is a natural rich green turquoise stone with a harsh transition to a lighter green near the top of the cabochon. Turquoise cabochons: A diverse collection of turquoise cabochons from various locations.

From left to right in the upper row: a greenish blue turquoise cabochon with black matrix from China; a teardrop-shaped, slightly greenish blue turquoise cabochon from Arizona's Sleeping Beauty Mine; and, two sky-blue turquoise cabochons with chocolate brown matrix from the Altyn-Tyube Mine in Kazakhstan. In the center row: a small sky-blue turquoise cabochon from the Kingman Mines in Arizona; and, two small round sky-blue cabochons from the Sleeping Beauty Mine of Arizona.

In the bottom row: two small cabochons with black matrix from unknown mines in Nevada; a teardrop-shaped cabochon with slightly greenish blue turquoise in black matrix from the Newlanders Mine in Nevada; and, a rectangular cabochon of slightly greenish blue turquoise in reddish brown matrix from the 8 Mine in Nevada.

Turquoise is an opaque mineral that occurs in beautiful shades of blue, bluish green, green, and yellowish green. It has been treasured as a gemstone for thousands of years. Isolated from one another, the ancient people of Africa , Asia , South America and North America independently made turquoise one of their preferred materials for producing gemstones, inlay, and small sculptures.

Its only important use is in the manufacture of jewelry and ornamental objects. However, in that use it is extremely popular - so popular that the English language uses the word "turquoise" as the name of a slightly greenish blue color that is typical for high-quality turquoise. Very few minerals have a color that is so well known, so characteristic, and so impressive that the name of the mineral becomes so commonly used. Only three other minerals - gold , silver , and copper - have a color that is used more often in common language than turquoise.

Turquoise cabochons: Turquoise cabochons from many parts of the world, showing a diversity of color and matrix. Image copyright iStockphoto, IrisGD.

Turquoise Rough and Cabochons: A small collection of turquoise cabochons and pieces of uncut turquoise. Click to enlarge. Blue minerals are rare, and that is why turquoise captures attention in the gemstone market. The most desirable color of turquoise is a sky blue or robin's-egg blue. Some people inappropriately describe the color as "Persian blue" after the famous high-quality material mined in the area that is now known as Iraq.

Using a geographic name with a gem material should only be done when the material was mined in that locality. After blue, bluish green stones are preferred, with green and yellowish green material being less desirable. Departure from a nice blue color is caused by small amounts of iron substituting for aluminum in the turquoise structure.

The iron imparts a green tint to the turquoise in proportion to its abundance. The color of turquoise might also be altered by small amounts of iron or zinc substituting for copper in the turquoise structure. Some turquoise contains inclusions of its host rock known as matrix that appear as black or brown spider-webbing or patches within the material. Many cutters try to produce stones that exclude the matrix, but sometimes it is so uniformly or finely distributed through the stone that it cannot be avoided.

Some people who purchase turquoise jewelry enjoy seeing the matrix within the stone, but as a general rule, turquoise with heavy matrix is less desirable.

Some turquoise localities produce material with a characteristic color and appearance. For example, the Sleeping Beauty Mine is known for its light blue turquoise without matrix. Much of the turquoise from the Kingman Mine is bright blue with a spider web of black matrix. The Morenci Mine produces a lot of dark blue turquoise with pyrite in the matrix. Much of the Bisbee turquoise has a bright blue color with a chocolate brown matrix.

People who know turquoise can often, but not always, correctly associate a stone with a specific mine. The best way to learn about minerals is to study with a collection of small specimens that you can handle, examine, and observe their properties. Inexpensive mineral collections are available in the Geology. Turquoise has a lower-than-ideal hardness and durability for use in certain types of jewelry. Although the gem is frequently used in rings, bracelets, and belt buckles, these uses place the gem at risk for abrasion and impact.

Smart jewelry design will surround the gem with a durable bezel that protects the sides of the gem from abrasion and impact. The bezel should be high enough to also protect the face of the gem.

Even if the gem is protected by a bezel, turquoise jewelry should be worn with care and respect. Avoid wearing it during activities that put the gem at risk, and store it where it will not be scratched by other items of jewelry. Turquoise is often porous, with the ability to absorb liquids.

These liquids can include perspiration, body oil, cleaning products, or any liquid that accidentally comes in contact. Once absorbed, these liquids can damage the turquoise or alter its color. If contact with cosmetics or potentially damaging liquid occurs, the turquoise should be washed with a soft cloth that is dampened with a very mild soap solution, followed by cleaning with a soft cloth that has been dampened with plain water.

Then, after the turquoise is dry, store it in a jewelry box away from bright light or heat. Turquoise rough: A specimen of rough sky blue turquoise in host rock from Mohave County, Arizona. Turquoise is rarely found in well-formed crystals.

Instead it is usually an aggregate of microcrystals. When the microcrystals are packed closely together, the turquoise has a lower porosity, greater durability, and polishes to a higher luster. This luster falls short of being "vitreous" or "glassy. Turquoise forms best in an arid climate, and that determines the geography of turquoise sources. Most of the world's turquoise rough is currently produced in the southwestern United States , China , Chile , Egypt , Iran , and Mexico.

In these areas, rainfall infiltrates downward through soil and rock, dissolving small amounts of copper. When this water is later evaporated, the copper combines with aluminum and phosphorus to deposit tiny amounts of turquoise on the walls of subsurface fractures. Turquoise can also replace the rock in contact with these waters. If the replacement is complete, a solid mass of turquoise will be formed. When the replacement is less complete, the host rock will appear as a "matrix" within the turquoise.

The matrix can form a "spider web," "patchy" design, or other pattern within the stone. The physical properties of turquoise are valuable for its identification. They are also valuable information for the care of turquoise jewelry. Important properties are summarized in the accompanying table. Weathering can significantly alter the physical properties of turquoise. Weathered turquoise might still have a desirable color, but its hardness and durability are reduced.

This turquoise cannot be cut into useful cabochons or beads. It might also have veins of matrix running through it matrix is a remnant of its surrounding rock. The material known as spiderweb turquoise contains fine seams of matrix that form attractive web-like patterns. The most valuable turquoise is an even medium blue, with no matrix and the ability to take a good polish.

Turquoise is most often cut as a cabochon. In addition, manufacturers and artisans fashion turquoise into round or oblong beads for strand necklaces, and into small, flat pieces that are popular in jewelry inlays. Some top-color blue turquoise is engraved with Persian or Arabic inscriptions, inlaid with gold.

Turquoise is weighed in carats, and five carats equal one gram. Turquoise is available in a wide range of sizes.