Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminium, with the chemical formulaCuA16 (po4)4(OH) 8.4H20. lt is rare and valuable in finer grades and has been prized as a gemstone and ornamental stone for thousands of years owing to its unique hue. ln recent times, turquoise has been devalued, like most other opaque gems,
