Opal is a hydrated amorphous form of silica. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl, and basalt. Precious opal ranges from clear through white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. Of these hues, the black opals are the rarest, whereas white and greens are the most common.
Gold(14K) A coating of gold is deposited on the item using the galvanic method or IP process. It is mixed with other metals, usually silver or copper, to make it less expensive, harder, and longer lasting while preserving the brilliance of pure gold. 14k gold is 14/24 of pure gold, which is approximately 58.3% pure gold.