Widely known as the October birthstone, opals are beautiful miracles of nature that come in several types, with each type having its own characteristics. When you hear the word "Opal", an image of a milky white stone dazzling in the sunlight, reflecting a rainbow of vibrant colors, must have crossed your mind. But are you aware of the fact that there are actually 4 various types of Opal, including white, black, and other variety of colors in between. These types can be further broken down into nearly 20 subtypes. This blog will help you learn about the different types of opal, so that you can have good knowledge about these gemstones and choose one accordingly.
Classifying Opals
Opals can be categorized in several ways, but the five primary types are White Opal, Jelly Opal, Boulder Opal, Black Opal, and Fire Opal. This classification often relates to the stone's "backdrop" color. Opals consist of tiny silica spheres that reflect various colors within the stone, meaning that a "White Opal" has a white base color, which can be either completely white or even feature bright color patches.
Opals can also be classified by their mining regions, such as Australian Opal or Ethiopian Opal; both of which are among people's favourites currently. Additionally, Opals can be considered phenomenal or non-phenomenal, with the phenomenal ones reflecting the vibrant play of colors that Opals are famous for. While the non-phenomenal one doesn't have the same. In this blog, we will discuss the phenomenal varieties because that is what people love and know.
The Most Common Type: White Opal
In the US, White Opals are the commonly found Opal type, likely due to their accessibility. With numerous productive White Opal mines, particularly in Australia, they are relatively easier to find and thus are more affordable as well.
Australian Opal and Ethiopian Opal
Both Ethiopian and Australian opals belong to the Jelly opal family, which features a more translucent backdrop, causing the vibrant colors to dance off a nearby clear stone.
Typically, most Australian and Ethiopian opals display shades of blue, ranging from cerulean to indigo, but the color variety options are endless. These two gemstones may look alike; however, their origin are different. Australian Opal gemstones are mined deep within the Earth's crust, while Ethiopian Opals are found on the hillsides in volcanic deposits. Both these gemstones have the silica sphere structure, but they are affected by their surroundings.
Notably, Ethiopian opals are known as Hydrophane Opals, which means they can absorb and release water, while Australian Opals, having less moisture content, are more durable.
The Fiery Variety: Mexican Opal
Although not all fire opals originate from Mexico, and not all Mexican opals are fire opals, the country is famous for them. Mexican Fire Opals are usually bright orange, but can range from yellow to deep red. These stones have a unique crystalline structure, which provides them with sharp edges unlike other Opals, and some of them even resemble Ruby or Orange Topaz.
Additionally, many Mexican Opals have their original host rock, often Rhyolite or another volcanic type, giving them a unique apperance.
The Rarest Gem: Black Opal
Black opals are the rarest type of Opal, making them highly sought-after and quite pricey. They primarily come from a few mines, with the Lightning Ridge in New South Wales, Australia, being the most notable. Black opals are not just loved for their uniqueness but also for their absolute beauty. Featuring a black blackdrop, Black opals display vibrant colors that can create amazing patterns that often appear more colorful than black.
Nature's Beauty: Boulder Opals
If you are attracted to the look of Black opal but wish to spend less, Boulder Opal is a great alternative. While still reflecting beautiful contrasting colors, Boulder Opals are naturally formed with the host rock intact, making them more durable than other Opals. Some of them will still have tiny host rocks and may closely resemble Black opal, while others particularly feature the host rock running through the opal like a matrix.
Durable Doublets
Doublets are a popular choice in jewelry, as they combine natural Opal with another stone as a base. This serves two main purposes: if a dark stone is used, it beautifully highlights the opal's colors, allowing you to have a Black opal look but for less. Also, the backing enhances the durability of the stone, making it suitable for people with active lifestyles.
Taking Care of The Precious Opal Stone
Regardless of the type of Opal you choose, it is vital to take extra care of it properly. With a hardness rating of 5-6.5 on the Mohs scale, Opals are suitable for jewelry but lack the scratch resistance of harder stones like Topaz or Tourmaline.
Store Opal stone in a separate cloth bag or box to protect it from scratching. Some Opals, particularly Ethiopian Opals, are more delicate due to their porous nature, so it's essential to keep them dry. Boulder Opals and Doublets are more durable due to the additional stone layers they have.
Always avoid exposing your Opals to harsh chemicals, including perfumes and sunscreens, as this can damage them, so it is best to leave them at home during beach outings.
