Folks who know their turquoise can tell you what mine a particular specimen came from based on its color and matrix pattern. The differences can be very subtle, however, and the breadth of variation is enormous.

History and Folklore:
Old European tradition associates turquoise with horses. Turquoise supposedly protected horses from all manner of ills, including drinking overly cold water when overheated.

The bearer of turquoise should be able to resist evil and maintain virtue.

Tibetans believe that turquoise brings good fortune and health, and wards off the evil eye.

Turquoise was more valuable than gold to the Aztecs of Mexico - a notion that was passed on to the conquering Spaniards.

The name "turquoise" is fairly recent. Pliny referred to it instead as callais, with comes form the Greek kalos lithos meaning "beautiful stone."

One who sees the reflection of the new moon on turquoise will have good luck, according to Persian legend. The Hindus thought a similar combination would bring great wealth. And the Navajos thought that a prayer spoken while throwing turquoise into the river would bring rain.

Imitators:
Dyed chalcedony, dyed howlite, glasses, ceramics, and plastics. Pieces of turquoise are pulverized and reconstituted to look like natural turquoise. There are some other minerals that can be confused with turquoise: amazonite, chrysocolla, lazulite, hemamorphite, odontolite, serpentine, smithsonite, faustite, prosopite, and variscite.

Even the early Egyptians imitated turquoise with a glazed quartz paste (faience) due to the inferior quality of the available turquoise.

Lab-Grown (synthetic):
This is marketed under such names as hamburger turquoise, neolite, and neo-turquoise.