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Barite (Baryte)
Chemical composition BaSO4
Crystal system Orthorhombic
Habit Tabular parallel to base, fibrous, nodular to massive
Cleavage Perfect cleavage parallel to base and prism faces: {001} Perfect, {210} Perfect, {010} Imperfect
Fracture Irregular/uneven
Hardness 3-3.5
Optic nature biaxial +
Refractive index nα = 1.634–1.637
nβ = 1.636–1.638
nγ = 1.646–1.648
Birefringence 0.012
Specific gravity 4.3–5
Lustre Vitreous to pearly
Diagnostic Features High specific gravity, characteristic cleavage and crystals