Introduction
Opal is a gemstone known for its varying colours and play of light. Most opals are located in Australia, where they’ve been mined since the mid-1800s. However, there are also opal mines in Mexico, Siberia, and Brazil. Opals can be found in black opals, boulder opals, and crystal opals. Here’s an overview of each type of this beautiful gemstone:
Black opals
Black opals are the most common type of opal and can be found in Australia. While they have been discovered worldwide, black opals are generally associated with Australia. When cut and polished, these stones tend to have a black body colour, but their play of colour can range from greyish-green to blue or violet. Black opals are also known for having a dark background colour that makes their fire pop even more than regular white or brownish types will do.
Boulder opals
Boulder opals are found in Australia, typically mined from the ground. They can be black, blue, or yellow and have a hardness of around 3 to 4 on the Mohs scale (the same as glass). Boulder opals are small and relatively opaque—they have little to no play of colour. They’re also porous; if you put them underwater, you’ll see air bubbles come out of their cracks.
Boulder opals are similar to crystal quartz (which has an exterior patterned with dots). Still, crystal quartz isn’t an opal: it’s glassy enough that it doesn’t form any internal fractures or layers like a real gemstone.
Crystal opals
There are many types of opal, but they all have one thing in common: they’re made up of tiny translucent fibres that refract light in every direction. Crystal opals are the most common type, and you can easily find them in Australia. Crystal opals are usually white or grey, which makes them look more like glass than jewels. Consider buying a crystal opal ring instead if you want to wear something with a little more pop and shine.
White opals
White opals are the most common type of opal. They’re usually found in Australia, Brazil, and Mexico. White opals are the least expensive because they tend to have a more porous structure than other opals. They also have very little fire (the “glow” that comes from certain types of light), which makes them less desirable for jewellery purposes. However, white opal is still a favourite among many people because it’s so easy to find and affordable!
Many people prefer white over black or other coloured types when buying their first piece; however, if you want something with some fire, this might not be your best choice.
Overview of the three main types of opals.
Opal is a gemstone that comes in a variety of colours. There are three main types of opals: black, white, and crystal.
The most valuable type of opal is the black one because its play of colour is the most prominent. This opal colour ranges from dark grey to blue, green, and brown (like a seashell). It comes from Australia, Mexico, and Ethiopia.
White opals are extremely common because they’re made up of cristobalite—the same mineral that makes up quartz. This means they have no colour and only shine when light hits them at certain angles (hence “play-of-colour”). They come mostly from Australia but also from Brazil or Honduras.
Crystal opals have very little play-of-colour compared to their relatives but still, have enough lustre to make them beautiful stones. They come mainly from Queensland or South Australian mines near Lightning Ridge, where miners dig for them by hand since machines would break apart these fragile rocks easily! Boulder Opals.
Conclusion
Opals are beautiful gemstones that can be found in a variety of colours. While all opals have specific properties in common, such as being complicated and brittle, some varieties are more valuable than others due to their unique features. This article discusses the three main types of opal: black opal, boulder opal, and crystal opal.
