It's name is derived from the Greek word for blue. It can often have inclusions and streaks.
Having a variable hardness makes it quite difficult to cut.
Mined from Brazil, Burma, Kenya, Austria, Zimbabwe, Switzerland and the United
Color: Blue to colorless, brown,
Mohs' Hardness Scale: 4 to 7 depending on whether cut on axis or across
Density: 3.53 to 3.70
Transparency: Transparent to translucent