Yellow Opal

Natural opal is a semi-precious stone that is formed by the deposition of hydrated silica in the cracks and voids of volcanic rocks. Exposed natural opal has a round caboson shape, meaning it is cut and polished into a smooth convex shape without facets. The colour of natural opal is yellow but it can also show iridescence of other colours, such as green, blue or red, depending on the angle of light. The size of the stone is 5.00 mm and its approximate weight is 0.30 carats per stone. The clarity of this natural opal is very good, with no inclusions visible to the naked eye. The clarity of the stone is opaque or semi-opaque, i.e. it does not allow light to pass through it. The opal is untreated, i.e. it has not undergone any chemical or thermal process to improve its appearance or durability. Iridescence is strong, with a multicoloured glow that varies with the movement of the stone or light source. The origin of natural opal is Ethiopia, one of the most important sources of opals in the world.