Opals are one of the most strikingly beautiful gems, their rainbow of scintillating hues are widely used across the world.
There are few gems like the opal; its kaleidoscopic array of colours shine with the fiery red of rubies, the deep blue of sapphires, the verdant green of emeralds, and the striking yellow of topaz. Opals have a history that dates back to the earliest days of human civilization, and it has been used in all manner of jewellery up to this day. So let's take a look at one of the most colourful gems and dive into the history of opals and opal jewellery.
What Is An Opal?
Opals are a mineraloid, specifically hydrated, amorphous silica. Opals are formed in areas with seasonal rainfall and high heat; when rain showers down in these regions, the water filters down into the cracks of the ground, carrying the silica needed to form the gemstone. After the seasonal rain ceases and the cracks dry, the silica deposits remain inside the deep fissures within the sedimentary rock; these deposits then go on to form opals.
There are two classes of opal, precious and common, and each category has several different types within it:
Precious opals are those that show the scintillating array of colours the gemstone is known for, called a play-of-colour. The cause for this is the internal lattice of the opal; it contains closely packed silica spheres that interfere with and refract the light trying to pass through the gemstone, and how tightly packed these spheres are, and their orientation determines the nature and intensity of the colours of the opal. Precious opals come in a variety of types, but the most common are:
White Opal: The most common of the precious opal, it has a milky white colour as a backdrop for the play-of-colours.
Black Opal: This form of opal is rarer, and has a dark coloration combined with its play of colours.
Boulder Opal: This opal forms in ironstone boulders or sandstone; it has a blue or brown hue combined with its play-of-colours.
Water Opal: This opal is nearly clear with a slight blue-ish tint, with no contrast, its play-of-colours can appear less bright than others.
Common Opals do not show a play of colours and come in a host of colours, are often opaque, and have a glassy appearance; additionally, they can often be fluorescent. Common opals come in many different forms, but these are some of the most common:
Jasper Opals: These opals are reddish-brown and are named from their resemblance to jaspers.
Milk Opals: These milky-white stones have a blue, green, or yellow colouration.
Moss Opals: These stones are usually clear with green, brown, or black dendritic inclusion that resemble moss.
History Of Opal Jewellery
Opal has a long and storied history, with the earliest found opal artifacts found in a cave in Kenya, which is believed to have been mined in Ethiopia, dating back to 4,000bc. While the opal was used in jewellery by many ancient cultures, they were exceedingly rare and were thus only worn by nobility or the wealthy. However, that did not stop cultures from attributing qualities to the opal. The opal has been considered the most magical gem by civilizations across most of the world. For example, the Romans believed the gems were gifts from the gods and could grant prophetic powers. In Arabia, they believed that the heavens sent the gems through lightning. In England, it was said to contain the magical attributes of all other gems and could make one invisible if wrapped in a bay leaf, giving the nickname of "the thieves stone."
Throughout most of history, cultures have seen opals as a sign of good luck, prosperity, and healing; however, this changed in 1892 with the publication of Sir Walter Scott's Anne of Geierstein. In this novel, a character named Baroness of Arnheim with an opal amulet that granted her magical powers until holy water rendered it inert, changing its colour to a dull grey and killing her. Anne of Geierstein was incredibly popular, so much so that its portrayal of opals led to their association with death and bad luck.
Due to their scarcity, opals were not widely available for mass distribution until the world's largest source of opals were discovered in Australia in the late 19th century. In 1849 a Geologist named Johannes Menge found some of the first common opals in Angaston, Australia. After that, in the 1880s, miners began scouring the Queensland Boulder Opal and Lightning Ridge fields; precious opal harvesting began in White Cliffs, Opalton, in 1890 and Lightning Cliffs in 1905. In the early 1900s, opal mining and production fluctuated, but when large fields were found in 1946, Australia overtook Europe in the global opal market; later, in 1970, new opal cutting technology was introduced by Des Burton that revolutionized the opal mining industry.
Today, opals can be found in jewellery stores worldwide; once the original October birthstone, it is now a popular favourite of many for its scintillating colours and awe-inspiring beauty. At Odissa, we have a large selection of high-quality opal jewellery from local artisan crafters in the UK that you can browse here, or you can browse our entire catalog here. If you would like to read more about different kinds of jewellery and gemstones, you can view our blog here, or if you want to sell through us or inquire about becoming a member of the Guild of Jewellery Designers, you can contact us here.