Black Tourmaline A cut base Sunstone is a variety of

Sunstone is a variety of microcline or oligoclase feldspar

Average measurements: 3

3 inches in height and length

They average 0

Septarian are carbonate rich concretions containing angular cavities and cracks filled with hardened material

Black Tourmaline A cut base Sunstone is a variety ofBlack Tourmaline, scientifically known as Schorl, can originate from the crystallization of molten rock deep within Earth's crust. It has a hardness of 7 7. 5 on Mohs scale with a trigonal crystal structure. The black color is often due to the presence of iron impurities within the crystal structure. This particular specimen is from Namibia, South Africa. Measuring . 6 inches in height, 1. 2 inches in length, and 1 inch in width. Weighing 1. 2 ounces.