Gemstones

Characteristics of Andalusite

Characteristics of Andalusite: Chemical Name: Aluminum silicate Formula: Al2(SiO4)O Colors: Pink, brown, white, grey, violet, yellow, green, blue Structure: Orthorhombic Hardness: 7.5 Specific Gravity: 3-3.2 Refractive Index: 1.63-1.64 Lustre: Vitreous...

Characteristics of Topaz

Characteristics of Topaz: Chemical Name: Aluminum fluorosilicate Formula: Al2(F,OH)2SiO4  Colors: Yellow, golden, orange, pink, green, blue, colorless Structure: Orthorhombic Hardness: 8 Specific Gravity: 3.5-3.6 Refractive Index: 1.62-1.63 Lustre: Vitreous Streak:...

Characteristics of Zircon

Characteristics of Zircon: Chemical Name: Zirconium silicate Formula: ZrSiO4  Colors: Reddish brown, yellow, green, blue, grey, colorless Structure: Tetragonal Hardness: 6.5-7.5 Specific Gravity: 3.9-4.7 Refractive Index: 1.81-2.02 Lustre: Vitreous to...

Characteristics of Garnet

Characteristics of Garnet: Chemical Name: Formula: (Fe,Mg,Ca,Mn)3(Al,Fe)2Si3O  Colors: Black, brown, yellow, green, red, violet, orange, pink Structure: Cubic Hardness: 7-7.5 Specific Gravity: 3.6-4.3 Refractive Index: 1.73-1.94 Lustre: Vitreous Streak: White...

Characteristics of Peridot

Characteristics of Peridot: Chemical Name: Magnesium, iron silicate Formula: (Mg,Fe)2SiO4  Colors: Pale green to brownish-green Structure: Orthorhombic Hardness: 6.5-7 Specific Gravity: 3.32-3.37 Refractive Index: 1.64-1.69 Lustre: Vitreous to greasy Streak:...

Characteristics of Zoisite

Characteristics of Zoisite: Chemical Name: Calcium aluminum-silicate Formula: Ca2Al3 (OH) Si3O12  Colors: Blue, pink, white, light brown, green, grey Structure: Orthorhombic Hardness: 6.5-7 Specific Gravity: 3.2-3.4 Refractive Index: 1.69-1.70 Lustre: Vitreous...