Opal is not one stone but a whole family, and the names get used loosely enough to confuse anyone. Some types are named for their body tone, some for the rock they grew in, some for where they came from. Once you see how the names are grouped, the whole subject falls into place. Here is the complete list as I use it at the bench, with a word on each and where to read more.
Types named by body tone
Body tone is the background of the stone, and it is the first thing I look at, because it drives both the look and the price.
Black opal has the darkest body, which makes its color look the most intense. The finest comes from Lightning Ridge and reaches the highest prices in the opal world.-
Dark or semi-black opal sits a step lighter than true black, with a gray body. It offers much of the drama for less money.
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White opal, also called light or milky opal, has a pale body and a soft, pastel play-of-color. It is the most widely available and a lovely first opal.
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Crystal opal is transparent to translucent, so the color seems to float inside the stone. Clarity plus bright color makes a fine crystal opal genuinely valuable.
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Jelly or water opal is a clear, glassy stone with gentle flashes of color drifting through it.
Types named by their host rock
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Boulder opal forms in seams inside ironstone and is cut with that brown host rock left on the back. The backing makes it tough, which is why I reach for it so often in rings.
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Matrix opal has opal scattered through the host rock as a network of color rather than a solid band, giving a speckled, all-over effect.
Found a type you like the sound of? Browse the handcrafted opal rings in my collection, or ask me about a custom piece in the opal of your choice.
Types named by color or origin
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Fire opal is named for its warm body color, the oranges and reds most often found in Mexican material. Some shows play-of-color and some is loved simply for its glow.
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Ethiopian opal, much of it from the Welo region, arrived in quantity recently and offers vivid color at a friendly price. A lot of it is hydrophane, meaning it can absorb water, so it asks for a little more care.
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Australian opal is less a single type than the benchmark the trade measures everything against, prized for its stability and range.
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Common opal, or potch, shows no play-of-color. It can still be a pleasant solid color and turns up in jewelry, but it is the plain cousin of the precious stones above.
A word on doublets and triplets
You will also see doublets and triplets offered. These are not a natural type. A doublet glues a thin slice of opal onto a dark backing, and a triplet adds a clear cap on top. They can look bright, but they are assembled stones and worth far less than a solid natural opal. It is worth knowing the difference before you buy.
Which type should you choose?
For a ring you will wear often, I usually point people toward Australian or boulder opal, since both stand up to daily life better than most. For the most color per dollar, Ethiopian is hard to beat. And for a piece to treasure, a fine black or crystal opal is the one that stops people in the street. For the rarer named patterns and varieties, see my guide to rare opal varieties.
Frequently asked questions
How many types of opal are there? It depends how you count, but the main types are black, dark, white, crystal, jelly, boulder, matrix, fire and common opal, plus origin labels like Australian and Ethiopian. They overlap, since one stone can be both crystal and Ethiopian, for example.
What is the most valuable type of opal? Black opal, especially from Lightning Ridge with bright red play-of-color, reaches the highest prices. I explain why in how much is opal worth.
Is fire opal the same as opal with fire? No, and this trips people up. Fire opal refers to the warm orange body color. The rainbow flash in any opal is called play-of-color, which is a different thing.
For the full picture of what opal is, how its color works and what drives value, see my guide to understanding opal. Or browse the current opal rings and find the type that speaks to you.
