Arizona Rocks and Minerals
“Turquoise crystals are so rare that most collectors don’t even know that they can exist. Instead, turquoise often occurs as compact seams filling cracks within broken brown or white rocks. This massive form of turquoise, while hard, is often unstable and crumbles easily. Because of this, only the finest, most solid specimens will take a good polish,”
- Arizona Rocks and Minerals by Bob Lynch and Dan R. Lynch