Turquoise
While turquoise is usually associated today with Native American culture, the ancient Egyptians were mining turquoise in 3200 BC. Many ancient cultures regarded turquoise as a source of metaphysical power. Turquoise was thought to protect from evil, maintain virtue, and bring good luck.

Turquoise is an opaque, light to dark blue or blue-green gem. The finest color is an intense blue. Turquoise may contain narrow veins of other materials either isolated or as a network. They are usually black, brown, or yellowish-brown in color. Known as the matrix, these veins of color are sometimes in the form of an intricate pattern, called a spider web.

To improve its color and durability, turquoise is commonly permeated with plastic, a permanent enhancement. It is also sometimes permeated with colorless oil or wax, which is not a permanent enhancement. Some turquoise is dyed to improve its color, but rarely, as this is not a permanent enhancement.

Special care is required for turquoise regardless of whether or not it is enhanced. A porous gem, turquoise can absorb anything it touches. Avoid contact with cosmetics, perfumes, skin oil, acids, and other chemicals. Avoid dehydrating it or exposing it to heat.