Gold Firoza Turquoise Jhumki Jewellery

Gold Firoza Turquoise Jhumki Jewellery

Turquoise

Turquoise-40031.jpg

General

Category Phosphate minerals

Formula

(repeating unit) CuAl6(PO4)4(OH)8·4H2O

Strunz classification 8.DD.15

Crystal system Triclinic

Crystal class Pinacoidal (1)

(same H–M symbol)

Identification

Colour Turquoise, blue, blue-green, green

Crystal habit Massive, nodular

Cleavage Good to perfect_usually N/A

Fracture Conchoidal

Mohs scale hardness 5–6

Luster Waxy to subvitreous

Streak Bluish white

Specific gravity 2.6–2.9

Optical properties Biaxial (+)

Refractive index nα = 1.610

nβ = 1.615

nγ = 1.650

Birefringence +0.040

Pleochroism Weak

Fusibility Fusible in heated HCl

Solubility Soluble in HCl

References