Turquoise beads are a gemstone of ancient origin occurring in the whole range of hues from sky blue to grey-green. The material has black or brown veins or blotches running through it, which are known as `turquoise matrix`. Deposits are in the USA, Mexico, Israel, Iran, Afghanistan and China. Turquoise treatments may include waxing, color enhancement, and `reconstructed turquoise` made from pulverized turquoise.