Black Opal — Gem Rough

$7,321.32
Chemical FormulaSiO₂·nH₂O
Crystal SystemAmorphous
Mohs Hardness5.5–6.5
Specific Gravity2.15
LusterVitreous to resinous
TransparencyOpaque with play-of-color

Lightning Ridge black opal is the most valuable gem variety on a per-carat basis that the Earth produces routinely. The ‘black’ refers to the dark body tone, which provides the bac…

Only 1 available — a rare find.

SKU: TC-GEM-0350
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Description

What looks like stone is, on closer inspection, frozen time. Lightning Ridge black opal is the most valuable gem variety on a per-carat basis that the Earth produces routinely. The ‘black’ refers to the dark body tone, which provides the backdrop against which play-of-color — caused by diffraction from stacked silica spheres of uniform size — blazes most intensely. Each opal’s pattern is unique, a frozen snapshot of spheres arranged by sedimentation 100 million years ago.

This specimen originates from Lightning Ridge, New South Wales, Australia, one of the world’s most significant localities for this type of material. Collectors and scientists have drawn from this region for generations, and for good reason: the combination of geological conditions here produces specimens of exceptional quality and clarity.

Every specimen is unique. Photographs approximate the visual experience, but the real thing — its weight, its luster under a raking light, the way it catches the corner of your eye — can only be experienced directly.

Formation

This specimen formed through geological processes operating over timescales that dwarf human history. The specific combination of chemistry, temperature, pressure, and time at this locality produced material of exceptional quality that makes it a valued addition to any serious collection.

Locality

Black Opal — Gem Rough from Lightning Ridge, New South Wales, Australia. This locality is known for producing specimens of exceptional quality.

Collector Notes

Best displayed where natural light can play across the surfaces at different times of day.