What is Black Crystal Opal?

Black crystal opal is a rare and captivating variety of opal known for its translucent body tone and rich play-of-colour. While similar to black opal in appearance, black crystal opal allows light to pass through it when held up giving it a unique depth and glow that sets it apart from other opal types.

What Makes Black Crystal Opal Unique?

Black crystal opal features a clear to semi-transparent body tone with a subtle dark base. When viewed in hand, it may appear like a traditional black opal, but under light, you’ll notice the internal structure becomes visible revealing layers of colour and texture. This rare optical effect is caused by the stone’s internal transparency combined with its dark backing.

Because of this, black crystal opals are often mistaken for either black or crystal opals. But that is not the case. They are their own distinct category.

Where Is Black Crystal Opal Found?

The majority of black crystal opals are mined in Lightning Ridge, Australia, one of the world’s most famous opal towns. These opals are often discovered mixed within other types of opal-bearing strata, making them especially hard to source in large quantities. Nature doesn’t easily replicate the conditions needed to form this type of gem, which adds to its rarity and appeal.

How Much Is Black Crystal Opal Worth?

Due to their rarity and beauty, black crystal opals can reach prices up to $6,000 USD per carat, depending on their colour play, brightness, and size. Like black opal, they come in a full spectrum of colours like reds, greens, blues, oranges, and purples, with the finest specimens being highly sought after by collectors and jewellers around the world.

Cutting and Polishing Black Crystal Opal

For lapidaries, black crystal opal is a relatively easy material to cut. Its slight transparency allows cutters to see into the stone and assess any inclusions, cracks, or sand spots that may affect shape or yield. This visibility helps reduce cutting risk and makes it easier to plan for symmetrical or free-form shapes.

In some cases, black crystal opals can be polished on both sides, resulting in double-sided opals. These are particularly popular in pendant designs and flipping-style jewelry, as they showcase colour from every angle and increase the gem’s overall value.

Buyer Beware: Mislabelled Opals

Not all opals sold as “black crystal” are the real deal. Some are simply black opals with slightly lighter tones or improperly identified crystal opals. At Black Opal Direct, we always ensure our opals are properly graded and sourced directly from Lightning Ridge so you know exactly what you're getting.