Different Types of Opal
Opals are one of the most fascinating gemstones in the world. Known for their dazzling colours and unique play of light, opals have captured the imagination of humans for centuries. These gemstones are formed from silica gel, seeping into rock cracks and fissures and hardening over time. As the light passes through the silica spheres, it is diffracted and reflected, creating the stunning array of colours that opals are known for. Opals come in various types, each with its distinct qualities and characteristics. This article will elaborate on some of the different types of opals.
1. White Opal
White opal is the most common type of opal and is found in abundance in Australia. As its name suggests, this opal has a white or light-coloured base with a play of colour that ranges from subtle to vibrant. The most common colours noticed are blue, green, and pink. They are usually found in small sizes and are popular in jewellery due to their affordability.
2. Black Opal
Black opals are some of the rarest and most sought-after opals worldwide. They are found primarily in Lightning Ridge, Australia, and are characterised by their dark body tone, which provides a striking backdrop for the play of colour. Black opals can display various colours, including red, orange, green, blue, and purple, and are highly valued for their intensity and vibrancy. The most prized black opals are those with a black body tone and a broad, vivid play of colour.
3. Boulder Opal
Boulder opals are unique in that they form within ironstone boulders rather than in cracks and fissures in rocks. The ironstone creates a natural backing for the opal, ranging from white to black. Boulder opals are found primarily in Queensland, Australia, and are characterised by their earthy, natural appearance. They often display a mix of colours, including blue, green, and yellow, and can be cut into various shapes and sizes.
4. Crystal Opal
Crystal opals are prized for their transparency and clarity, which allows for a vivid display of colour. Unlike white opals with a milky or opaque appearance, crystal opals have a clear or translucent body tone that allows the light to pass through unimpeded. Crystal opals are found primarily in Coober Pedy and Andamooka, Australia, and can display various colours, including red, orange, green, blue, and purple.
5. Fire Opal
Fire opals are a type of Mexican opal known for their fiery orange, yellow, and red colours. These opals are formed from silica deposits in volcanic rocks and are characterised by their warm, intense colours. Fire opals are usually transparent or translucent and can be cut into various shapes and sizes. They are not typically used in traditional opal jewellery due to their softness and tendency to crack.
6. Ethiopian Opal
Ethiopian opals are a relatively new discovery and have quickly become popular among opal enthusiasts. These opals are found in Ethiopia and are characterised by their bright, vivid colours and high transparency. Ethiopian opals can display various colours, including red, orange, green, blue, and purple, and are highly prized for their unique patterns and play of colour.
7. Matrix Opal
Matrix opals are a type of boulder opal that have a distinctive pattern of opal veins running through their host rock. This creates a beautiful and unique contrast between the opal and the surrounding matrix. Matrix opals can be found in different colours, including blue, green, and red. They are typically cut in freeform shapes to highlight the natural pattern of the opal veins.
In conclusion, opals are some of the world’s most captivating and unique gemstones. They come in various types, each with its distinct qualities and characteristics. Whether you prefer the earthy charm of boulder opals, the classic beauty of white opal or the intense colour of black or fire opals, there is an opal type to suit every taste and style.