Gemstones

Characteristics of Copal

Characteristics of Copal: Chemical Name: Copal gum Formula: C10H16O Colors: Light lemon yellow to orange Structure: Amorphous Hardness: 2.5-3 Specific Gravity: 1.05-1.10 Refractive Index: 1.54 Lustre: Resinous Locations: Malaysia, Philippines,...

Characteristics of Jet

Characteristics of Jet: Chemical Name: Carbon Formula: C Colors: Dark brown, black, Structure: Amorphous Hardness: 2.5-4 Specific Gravity: 1.30-1.34 Refractive Index: 1.66 Lustre: Waxy Streak: Black to dark brown Locations:...

Characteristics of Mother-of-pearl

Characteristics of Mother-of-pearl: Chemical Name: Calcium carbonate, calcium phosphate, amorphous silica Formula: CaCO3, Ca3(PO4)2, SiO2 Colors: All Structure: Amorphous Hardness: 3.5 Specific Gravity: 2.7-2.89 Refractive Index: 1.530-1.685 Lustre: Greasy to...

Characteristics of Shell

Characteristics of Shell: Chemical Name: Calcium carbonate, aragonite Formula: CaCO3 Colors: White, pink, silver, cream, brown, green, blue, black, yellow Structure: Amorphous Hardness: 3-4 Specific Gravity: 2.60-2.78 Refractive Index: 1.52-1.66...

Characteristics of Pearl

Characteristics of Pearl: Chemical Name: Calcium carbonate Formula: CaCO3 Colors: White, pink, silver, cream, brown, green, blue, black, yellow Structure: Amorphous Hardness: 2.5-4.5 Specific Gravity: 2.60-2.85 Refractive Index: 1.52-1.59 Lustre:...

Characteristics of Euclase

Characteristics of Euclase: Chemical Name: Beryllium silicate Formula: BeAlSiO4(OH) Colors: Colorless, white, blue, green Structure: Monoclinic Hardness: 7.5 Specific Gravity: 3 Refractive Index: 1.65-1.67 Lustre: Vitreous Streak: Colorless Locations: Brazil,...