Cat's Eye Opal
Cat's Eye Opal
is a rare chatoyant variety of opal that is sometimes traded as 'Opalite Cat's Eye'. However, 'opalite' is typically a term used to refer to a man-made opalised glass, whereas cat's eye is a completely natural type of opal. The chatoyant attribute gives this stone its popularity, which is known in the trade as a 'cat's eye effect'. This fascinating phenomenon is caused by fine inclusions within the stone. When a stone is viewed under a strong light source, it creates a bright line of light that runs perpendicular to its inclusions. The cat's eye effect can glide across the surface of the stone when it's turned under light. Cat's Eye Opal is typically greenish yellow, yellow-brown, or creamy honey color, and it exhibits a very strong cat's eye effect
. It also occurs in other colors, including shades of red, yellow, white, and black. Unlike many other varieties of opal
, Cat's Eye Opal often does not exhibit much color play, similar to fire opal
, as it valued more for its cat's eye effect
. However, high-quality specimens do show opalescence in addition to its chatoyancy. The combination of color play with cat's eye chatoyancy makes cat's eye opal a popular stone for opal-lovers, as well as gem collectors
. Many cat's eye opals are stabilized or impregnated, usually with synthetic resins, to enhance durability and appearance. As long as the treatment is disclosed, it's an acceptable treatment according to most gem and jewelry enthusiasts. Cat's eye opal is known to be found in Brazil, United States, and Africa (Madagascar and Tanzania).