Turquoise can be translucent or opaque with a color that usually ranges from light medium blue to greenish blue. It is often mottled and sometimes contains dark splotches or veins of black matrix running through it. In the case of spiderweb turquoise, fine seams of matrix form distinctive web like patterns. Although matrix may be desirable and attractive, the most valuable turquoise is considered to be an even medium blue, with no matrix at all. The best color is known in the trade as "robins egg" blue. The most important market for turquoise is the American Southwest where it is commonly set in silver as the focal point in many of the Native American designs.
Because turquoise is frequently too chalky or unstable and full of holes and cracks, it is often treated with dye or stabalized with plastic.
Turquoise supposedly helps one to start new projects. Turquoise has been thought to warn the wearer of danger or illness by changing color. In the 13th century, Turquoise was thought to protect the wearer from falling especially from horses. Legend has it that the Indians believed that if turquoise was affixed to a bow, the arrows shot from it would always hit their mark. It was also believed to bring happiness and good fortune to all.