Template:Danburite

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Danburite
Chemical composition CaB2(SiO4)2
                         Calcium Boro-Silicate
Crystal system orthorhombic
Habit prismatic
          with a rhombic cross section, a wedge-shape termination of dome
Cleavage indistinct
Fracture sub-conchoidal
Hardness 7.0-7.5
Optic nature biaxial +,-
Refaction index 1.630-1633 to 1636-1641
Birefringence 0.006
Dispersion low, 0.017
Specific gravity 3.00
Lustre vitreous
Pleochroism weak / not determinable
 Fluorescece : light blue (LW)