Turquoise
Turquoise pebble, one inch (25 mm) long. This pebble is greenish and therefore low grade
General
Category	Phosphate mineral
Chemical formula	CuAl6(PO4)4(OH)8·4H2O
Identification
Colour	Blue, blue-green, green
Crystal habit	Massive, nodular
Crystal system	Triclinic
Cleavage	Good to perfect - usually N/A
Fracture	Conchoidal
Mohs scale hardness	5-6
Lustre	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	[1][2][3]

Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue. In recent times turquoise, like most other opaque gems, has been devalued by the introduction of treatments, imitations, and synthetics onto the market.
The substance has been known by many names, but the word turquoise was derived around the 16th century from the French language turquie, for Central Asian^[4] material which was early

Loven how it is crazy, yet, subdued with the reds and pinks!!