





Opal is the traditional birthstone for October, and also the 14th anniversary gift. The name comes from the Sanskrit word upala
, which means "precious stone". The Latin word opalus
came into use during the Roman Empire.
Tradition, Mythology, & Metaphysical Properties
The opal has recently gained a reputation as unlucky for people who weren't born in October, but that is only because it is a fairly soft stone that can break easily. In fact, it has been regarded as a stone of luck and magic for centuries! The ancient Greeks believed it gave the gift of prophecy and protection from disease. Indian mythology says that the Virgin Goddess of the Rainbow was turned into an opal by the Mother Goddess because Brahma, Vishnu, and Shiva were pursuing her.
The opal corresponds to the sacral chakra, and imbalances can contribute to addictions. It is said to moderate and harmonize sexual desire, and is seen as a symbol of hope, purity, and truth. The "fire" of an opal is supposed to spark creativity, and the dance of the fire can help people enjoy life.
Click here for an article (with really cool pictures) on some of the most famous opals in the world, all found in Australia.
https://blog.stuller.com/sell-story-famous-opals/
Geological Properties
Properties: hardened silica gel with water content; all colors, translucent to opaque; Moh's hardness 5 1/2 - 6 1/2; specific gravity 1.98 - 2.20; refractive index 1.450
Opals are found in veins and cavities in igneous or sedimentary rock. The most valuable opals are found in Australia; they are also found in Brazil, Mexico, Czechoslovakia, southern Africa, and Nevada in the U.S. Synthetic opals have been around since the 1930s, but Gilson developed the first opalescent lab-created opal in 1973.
There are three kinds of opals: precious, fire, and common. Precious opal is opalescent, which means it has "fire" or "play of light". The stone is translucent, any color from white to black, with flashes of different colors, predominantly green, blue, and orange. These flashes are caused by interference from cristobalite spheres inside the silica gel. Fire opals are named for their color, ranging from yellow to red. They are usually milky, but can be transparent, and have no opalescence. Common opals are mostly opaque with little to no fire.
You may have recently heard of Ethiopian opal. It was first commercially mined in 2008, and is slightly stronger than most precious opal. An interesting fact about Ethiopian opal is that it is a "hydrophane" (water-loving) stone. Most opals are sedimentary, but these can actually absorb water, making them even more transparent.
There is also Peruvian opal, which is only found in the Andes mountains. It is sea green to blue, a relaxing color with occasional black dendritic inclusions. It is the national stone of Peru, and used to be thought a gift from Pachamama, the Incan goddess of Earth and Time.