Danburite

A clear calcium borosilicate whose crystals end in a chisel-like wedge.

Danburite specimen — Photo: Robert M. Lavinsky, CC BY-SA 3.0, via Wikimedia Commons

How to identify danburite

Clear prisms with wedge-shaped tips.
Hardness about 7.
No good cleavage.

Often confused with

Topaz
Topaz has a perfect cleavage across the crystal.
Compare side by side
Quartz
Quartz tips are six-sided pyramids, not wedges.
Compare side by side

Where it's found

Charcas, Mexico
Madagascar
Russia
Japan

Uses

Collector specimens and gemstones.

Rock tumbling

Great for tumbling.

Did you know?

It's named after Danbury, Connecticut, where it was first described in 1839.

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