Chemical Formula: (Fe2+,Mg)2(Fe3+,Sn)(BO3)O2 Locality: Brooks mountain, Seward peninsula, Alaska. Name Origin: Named for Alfred Hulse Brooks (1871-1924), U. S. Geologist.
Physical Properties
Cleavage: {110} Good Color: Black. Density: 4.3 Diaphaneity: Opaque Hardness: 3 – Calcite Luminescence: Non-fluorescent. Luster: Sub Metallic Streak: black
2(Fe3+,Sn)(BO3)O2 Locality: Brooks mountain, Seward peninsula, Alaska. Name Origin: Named for Alfred Hulse Brooks (187){kind=link}