Schorl is the black , iron-rich form of tourmaline, and is very common. The opaque, prismatic crystals may be several metres in length.

Schorl is found in pegmatites. During the Victorian era, black tourmaline was widely used for mourning jewellery, but today it has little, if any, value as a gemstone.

Chemical Composition: 

Complex borosilicate

Crystal System / Forms: 

Trigonal

Hardness: 

7.5

Specific Gravity: 

3.06

Lustre: 

Vitreous

Refractive Index / Birefringence: 

1.62-1.64 / 0.018

Cuts & Uses: 

Brilliant, Mixed.