Gemstones

Characteristics of Gypsum

Characteristics of Gypsum: Chemical Name: Calcium sulphate dihydrate Formula: CaSO4 2H2O Colors: Colorless, white Structure: Monoclinic Hardness: 2 Specific Gravity: 2.3 Refractive Index: 1.52-1.53 Lustre: Subvitreous to pearly Streak: White Locations:...

Characteristics of Alabaster

Characteristics of Alabaster: Chemical Name: Calcium sulphate dihydrate Formula: CaSO4 2H2O Colors: Colorless, white, yellow, light brown Structure: Monoclinic Hardness: 2 Specific Gravity: 2.3 Refractive Index: 1.52-1.53 Lustre: Subvitreous to pearly...

Characteristics of Celestine

Characteristics of Celestine: Chemical Name: Strontium sulfate  Formula: SrSO4 Colors: Colorless, red, green, blue Structure: Orthorhombic Hardness: 3-3.5 Specific Gravity: 4.0 Refractive Index: 1.62-1.64 Lustre: Vitreous, pearly on clevage Streak:...

Characteristics of Baryte

Characteristics of Baryte: Chemical Name: Barium sulfate  Formula: BaSO4 Colors: Colorless, golden, bluish, greenish, beige Structure: Orthorhombic Hardness: 3-3.5 Specific Gravity: 4.5 Refractive Index: 1.63-1.65 Lustre: Vitreous, resinous, pearly Streak:...

Characteristics of Lazulite

Characteristics of Lazulite: Chemical Name: Magnesium aluminum phosphate Formula: Colors: Various shades of blue Structure: Monoclinic Hardness: 5-6 Specific Gravity: 3.1 Refractive Index: 1.61-1.64 Lustre: Vitreous Streak: White Locations: Sweden,...

Characteristics of Apatite

Characteristics of Apatite: Chemical Name: Fluorapatite, chlorapatite, hydroxyapatite Formula: Colors: Various Structure: Hexagonal or monoclinic Hardness: 5 Specific Gravity: 3.1-3.2 Refractive Index: 1.63-1.64 Lustre: Vitreous, waxy Streak: White Locations: Madagascar,...