Turquoise gemstone is an opaque, blue-to-green gemstone. Its chemical composition is a hydrated phosphate of copper and alumiium. Most turquoise beads marketed these days is treated to strengthen is since real gemstone quality turquoise is hard to come by and extremely expensive. More of our turquoise necklaces are not antique or trule authenic, where this is the case we will state it. Typically we use treated turquoise since it has the same appearance and is less costly.