Color:
Light to dark blue or blue-green.
Gem family:
Turquoise
Birthstone:
One of the traditional birthstones of December.
History:
One of the oldest known gemstones, mined since 3200 BC. Worn by early Native Americans and Egyptian pharaohs.
Use in jewelry:
Various uses; commonly associated with jewelry from the southwestern United States.
Mohs hardness:
5-6 (1 softest to 10 hardest)
Common treatments:
Often permeated with plastic or with colorless oil or wax to improve color and durability. Sometimes dyed, but this approach isn’t common and may not be lasting. All treatments must be disclosed.
Care:
Because it is so porous, even if it has been treated, it can absorb substances on your skin like cosmetics, perfume or oil-based creams, which can affect color. Turquoise shouldn’t be exposed to extreme heat or light.