Blue Hackmanite 10mm Round - 15-16 Inch 48hr_five Norway where this type of

Norway where this type of igneous rock is found

It is a member of the Quartz family

grinding wheels and cutting disks

It also serves as the Mohs hardness scale index mineral for a hardness of 8

a banded Chalcedony that is predominantly white with layers of brown

Blue Hackmanite 10mm Round - 15-16 Inch 48hr_five Norway where this type ofDiscovered in Greenland in the late 1890's, hackmanite is named for Finnish geologist Victor Hackman. It is a rare occurrence to find gem grade hackmanite; at best, most crystals are translucent. Hackmanite is the light pink to pale violet variety of sodalite. It is a particularly unusual gem because it exhibits a special optical property known as "tenebrescence," a type of reversible photochromism. Hackmanite is very reactive under UV light.