Natural Arizona Turquoise Faceted Pear Drop Briolette Beads Strand Length 8 Inches and Size 11mm to 12mm approx.Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium. 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.