Definition of OPAL
Opals are essentially a gel from silica with percentages of water usually between 6% to 10%. Opal is 3% to 21% water weight , 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. Opal is the national gemstone of Australia. Opal hardness varies, but generally ranges from 5.5 to 6.5 on the Mohs scale. Compare that to diamond, which is rated at 10, and is the hardest gemstone.
Besides the gemstone varieties that show a play of color, there are other kinds of common opal such as the milk opal, milky bluish to greenish; resin opal, which is honey-yellow with a resinous luster; wood opal, caused by the replacement of the organic material in wood with opal.
Opal’s internal structure makes it diffract light; depending on the conditions in which it formed it can take on many colors. Opal ranges from clear through white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. Of these hues, the reds against black are the most rare, however white and greens are the most common. It varies in optical density from opaque to semi-transparent.
A Few Metaphysical Properties of Opal:
Known to bring out creativity, spontaneity, supports the kidneys and brings happiness, faithfulness, love, friendships, dreams, heals fevers and infections, self-expression, beauty, visions, fertility, eases child birthing process, boosts energy, supports reproductive system, lungs and third eye chakra. * Long ago, It was said that opal could make its wearer invisible.
Cites: Merriam-Websters,Wiki, About