Gemstones

Characteristics of Emerald

Characteristics of Emerald: Chemical Name: Aluminum beryllium silicate Formula: Be3Al2(SiO3)6 Colors: Emerald-green to green, yellow-green to blue Structure: Hexagonal Hardness: 7.5-8 Specific Gravity: 2.7-2.8 Refractive Index: 1.565-1.602 Lustre: Vitreous Streak:...

Characteristics of Tourmaline

Characteristics of Tourmaline: Chemical Name: Complex boron silicate Formula: NaFe 2+ 3Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH) Colors: Various Structure: Trigonal Hardness: 7-7.5 Specific Gravity: 2.8-3.3 Refractive Index: 1.61-1.67 Lustre: Vitreous Streak: White Locations: USA, Brazil, Czech...

Characteristics of Benitoite

Characteristics of Benitoite: Chemical Name: Barium titanium silicate Formula: BaTiSi3O9 Colors: Blue, colorless, pink Structure: Hexagonal Hardness: 6.5 Specific Gravity: 3.7 Refractive Index: 1.76-1.80 Lustre: Vitreous Streak: White Locations: USA, Belgium,...

Characteristics of Iolite

Characteristics of Iolite: Chemical Name: Magnesium, iron aluminosilicate Formula: (Mg,Fe) 2Al 4(Si 5AlO 18) Colors: Blue Structure: Orthorhombic Hardness: 7-7.5 Specific Gravity: 2.6 Refractive Index: 1.53-1.55 Lustre: Vitreous to greasy Streak: White Locations: Sri...

Characteristics of Sugilite

Characteristics of Sugilite: Chemical Name: Potassium, sodium lithosilicate Formula: KNa2(Fe,Mn,Al)2Li3Si12O30 Colors: Pink, brown-yellow, purple Structure: Hexagonal Hardness: 5.5-6.5 Specific Gravity: 2.73-2.79 Refractive Index: 1.60-1.61 Lustre: Vitreous Streak: White Locations: Canada,...

Characteristics of Dioptase

Characteristics of Dioptase: Chemical Name: Copper silicate Formula: CuSiO2(OH)2 Colors: Emerald- to blue-green Structure: Hexagonal/trigonal Hardness: 5 Specific Gravity: 3.3 Refractive Index: 1.67-1.72 Lustre: Vitreous to greasy Streak: Pale greenish-blue...