Opal is the birthstone for October, and it is a unique and beautiful gemstone with a fascinating history and symbolism.
Variety of Colours
Opals are known for their stunning play of colours, which can include flashes of red, green, blue, yellow, and more. This play of colours is caused by the diffraction of light as it passes through tiny silica spheres within the stone.
Formation
Opals are formed from silica gel that seeps into fissures and cavities in rocks. Over time, the water evaporates, leaving behind solid silica deposits. The play of colors in opals is a result of the arrangement of the silica spheres and the way they interact with light.
Types of Opals
White Opal An opal with a translucent to opaque white and other light colour backgrounds (body colour) with play-of-colour is called white opal.
Black Opal All other quality factors being equal, many people favour the dark background colour of black opal. This is partly because play-of-colour tends to stand out attractively against a dark background. The contrast of play-of-colour to body colour makes black opals very popular. Additionally, black opals are considered to be the rarest (white opals are more common). Fire Opal Fire opal is transparent to translucent with a body colour that is usually yellow, orange or red. This material, which might show play-of-colour, is also known as “Mexican opal” or “Mexican fire opal”.
Symbolism
Opals have been associated with various symbolic meanings throughout history. They are often seen as symbols of hope, purity, and innocence. Opals are also believed to bring good luck, as long as they are given as a gift rather than purchased for oneself.
Mythology and Folklore
Opals have a rich history of superstitions and beliefs. In ancient times, they were considered to possess magical properties and were often used for protection. However, some cultures also believed opals brought bad luck due to their shifting colours.
Care and Durability
Opals are relatively soft compared to other gemstones, so they require special care to prevent scratching and damage. They should be protected from extreme heat, rapid temperature changes, and chemicals. It's essential to store opals away from direct sunlight, as prolonged exposure can cause them to lose their play of colours.
Popular Opal Sources
Opals are found in various parts of the world, with significant deposits in Australia, including the famous Lightning Ridge and Coober Pedy mines. Other notable sources include Ethiopia, Mexico, and Brazil.