Shattuckite 8mm Star Cut Coin - 15-16 Inch 20210817 but also for industrial purposes

but also for industrial purposes from watch gears and scientific instruments to sandpaper and other abrasives

When the level of iron oxide is high

Many stones in the Russian crown jewels from the 17th century which were thought to be rubies are actually red Tourmaline

from light blue to lapis blue to cobalt

Shattuckite 8mm Star Cut Coin - 15-16 Inch 20210817 but also for industrial purposesShattuckite is a rare copper silicate hydroxide mineral. It occurs in bright turquoise blues and darker blues as well as rust reds, commonly with inclusions of copper in speckled patterns throughout the stone. Shattuckite is a pseudomorph, meaning it forms by replacing another minerals crystal structure atom by atom with its own crystal structure, with little alteration of the external shape of the original crystal.