This pair of sterling Silver earrings features a Natural Australian Light Opal, stamped with 925. Light Opal, also known as Crystal or White Opal, is classified by the Opal industry as Natural Opal Type 1. To qualify as Light Opal, the Opal must be presented in one piece, in its natural state, and possess a substantially homogenous chemical composition, as well as high translucency and freedom from oxides. Genuine Natural Australian Crystal Opal is a rare find in Andamooka, Lightning Ridge, Coober Pedy, and the Queensland Boulder Opal Fields. The Opal is a hydrated amorphous form of silica SiO2nH2O, which consists of closely packed planes of silicon dioxide molecules arranged in a regular pattern. Its clear crystal appearance and high translucency result from its pure hydrated silica SiO2nH2O composition, free from oxides such as Magnesium or Iron. Precious light Opal displays an interplay of internal colors, despite being a mineraloid with an internal structure. At a microscopic level, precious Opal consists of silica spheres in a hexagonal or cubic close-packed lattice, ranging from 150 to 300 nm in diameter.