Types of Opals
Black Opal this is the most precious and valuable of all Opals, and is mined mainly in Lightning Ridge NSW. The term “Black” refers to the body tone of the Opal which is distinguished by the blackness of the base or background which ranges from black to grey(sometimes referred to as “Dark Opal”). Some Black Opals show a degree of transparency these are referred to as “Crystal Black Opals”. High quality stones are very rare and valuable.
Boulder Opal the Boulder Opal is mined predominantly in the state of Queensland and forms in thin veins within its host rock(ironstone). When cut it is easily identifiable as the brown ironstone will form its backing. Due to the way it forms, it is almost always cut freeform in shape, giving it its unique characteristics. Boulder Opals are extremely popular due to their unique characteristics and also as they can display the same darkness and brilliance as a high quality Black Opal.
Crystal Opal this variety embraces Opal which is transparent or very translucent and is found in most Opal fields. The higher grade Crystal Opals show a distinct and very bright play of colour. High grade Crystal Opals are also quite rare and valuable.
Light/White Opal usually found in all Opal fields, but the bulk of the material coming from the South Australian fields of Mintabie, Coober Pedy and Andamooka. This Opal is distinguished by its light or milky body tone and is the most abundant of all Opals. However, high grade stones are quite rare and valuable.
Doublet Opal this is where a thin layer/veneer of Opal is glued or cemented to another backing to give the impression of a high grade Black or Boulder Opal, in fact Doublet Opals are quite invaluable and commonly used in fashion jewellery. For people who are looking for quality Opals, it is highly advisable to stay from Doublet Opals.
Triplet Opal this is a composition of three pieces, same as the Doublet opal with a third transparent piece affixed on top (usually glass or quartz) to enhance the colours. This type of Opals are very cheap and used in fashion jewellery. For people who are looking for quality Opals, it is highly advisable to stay from Doublet Opals.