Turquoise is an opaque mineral that occurs in beautiful colors ranging from light blue to blue-green to yellow-green. Chemically speaking, turquoise is a hydrous phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·5H2). Turquoise is seldom discovered in well-formed crystals. Instead it is typically an aggregate of micro crystals. When these micro crystals are tightly packed together, the resulting turquoise has greater durability, lower porosity and takes a high luster polish. The hardness of turquoise ranges from 5 to 6 on the Moh's scale making it hard enough for a turquoise engagement ring or turquoise wedding ring if worn with care. Turquoise forms best in an arid climate which explains why most of the world's turquoise rough is currently mined in the southwestern United States, China, Chile, Egypt, Iran, and Mexico. Turquoise forms when water percolates through rocks that contain copper, aluminum and other minerals. Complex chemical reactions take place over millions of years that result in the formation of turquoise deposits.
HISTORY OF TURQUOISE
Exactly when turquoise first came to the attention of man is unknown. Turquoise gets its name from the French expression pierre tourques, or “Turkish stone.” The name originated in the thirteenth century and reflects the fact that turquoise probably first arrived in Europe through Turkish sources.
One of the earliest known turquoise producing regions is Persia, now known as Iran. Historians believe turquoise has been mined there for more than 2,000 years. Turquoise collected from this region is known for its incredible robin’s egg blue color and is often called Persian turquoise.
The earliest record of turquoise being used in jewelry or in ornaments can be found in ancient Egypt. The Egyptian use of turquoise stretches back as far as the First Dynasty in 5500 BC when it was first used for beads. Turquoise was often combined with other ornamental stones and inlaid in gold by Egyptians to produce very sophisticated jewelry. The most well known works incorporating turquoise are those recovered from King Tut's tomb. Tutankhamun's death mask, perhaps one of the most recognized works of art in the world, is inlaid with turquoise, lapis, carnelian, amazonite and other stones.
The earliest known use of turquoise in North America was in the Chaco Canyon area of northwestern New Mexico. The use of turquoise by these Native Americans dates back to 2000 years ago. These ancient artists produced pendants, beads and inlay work out of turquoise. Native Americans held turquoise and objects carved from turquoise in high regard by were widely traded across the southwest and into South America. Early Native American turquoise jewelry designs were simple and did not use metal findings to secure the stones. It was not until the late 1800's when Native American jewelry artisans began using coin silver to make their silver turquoise jewelry. Their jewelry evolved into the turquoise and sterling silver Native American jewelry that is popular today.