Colemanite

Colemanite – CaB₃O₄(OH)₃·H₂O

Elements: Calcium, Boron, Oxygen, Hydrogen

Class: Borates

Crystal System: Monoclinic

Hardness: 4.5

Apatite

Talc (1)Diamond (10)

Softer than glass. A steel knife scratches it.

Origin: Kestelek Mine, Mustafakemalpasa District, Bursa Province – Turkey