Turquoise is one of the accepted birthstone for December and is the accepted anniversary gemstone for the 11th year of marriage. Other accepted birthstones for December are blue zircon (not recommended due to its softness), blue topaz and tanzanite.
Colors in turquoise range from sky blue (most desirable color) to blue green and apple green. When some people think of turquoise they only think of Native American jewelry. Today, turquoise is avaiable in many modern jewelry designs.
The name means "Turkish stone" because the trade route that brought it to Europe used to come via Turkey. The best qualities are found in northeast Iran (Persian turquoise). However, the United States southwest is now the world leader in production.
The deposits in Sinai were already worked out by 4,000 BC. At that time the stone was used for jewelry, amulets and in the preparation of cosmetics.
During the 16th century turquoise was used as currency by the Southwest Indians. They believed the gemstone could bring spoils to the warrior, animals to the hunter, and happiness and good fortune to all.
Although large quantities of beautiful turquoise which have not been color enhanced are available, today's turquoise is commonly stabilized with plastic to improve its color and durability. Chalky varieties of turquoise are normally impregnated with oil or wax to enhance color. This color change may not be permanent.
Care should be taken to protect it from scratches, sharp blows, hot water, and household chemicals. Do not use a home ultrasonic machine.