Lapis Lazuli-gemstone

Lapis Lazuli is a deep blue opaque gemstone,used in antiquity and continuously used throughout the generations. it still continues to be popular today,and remains one of the most important
opaque gemstone.lapis lazuli is chiefly composed of the mineral lazurite, with additional other minerals including white calcite and sparkling specks of pyrite.its a December birthstone .







Chemical Formula: ,,,,,,,,,,,,

Color                    : ,Blue,multicolored

Hardness              : 5-5.5

Crystal system      : Isometric

Refractive index   :  1.5

SG                        : 2.4 - 2.5

Transparency        :  Opaque

Double Refraction: .none

Luster                   :  Vitreous

Cleavage              :  3,6

Mineral Class       : Rock


Sources:
            Afghanistan, Russia .