Some crystals of Schorl can reach a rather large size and can display a great variety of crystal faces. Schorl can be a major component of igneous and metamorphic rocks. Although it is not the only black mineral common to such rocks, it is the only one that will form crystals with a clear triangular cross-section. This stone is unique with its long needle to straw sized, arrow straight, prismatic crystals of pitch black schorl criss-crossing the clear colorless quartz. This attractive stone is used in semi-precious jewelry, carved figurines, obelisks, crystal balls, eggs and as a popular tumbled stone.
Color is black.
Luster is vitreous to submetallic. The terminations can be either a simple to complex trigonal pyramid or flat basal face. The prism faces are usually striated lengthwise. In cross section, all tourmalines will appear predominantly triangular in shape. Doubly terminated crystals are hemimorphic meaning that the two ends of the crystal are not exactly alike.