Rocksday

Zoisite

A calcium aluminum silicate best known as green rock studded with red ruby crystals.

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

How to identify zoisite

  • Green massive stone, often with red ruby and black hornblende.
  • Pink variety (thulite) is opaque.
  • Hardness about 6.5.

Often confused with

Where it's found

  • Longido, Tanzania
  • Norway
  • Austria

Uses

Carvings and cabochons.

Rock tumbling

Great for tumbling.

Did you know?

It's named after Sigmund Zois, an 18th-century Slovenian patron of natural science.

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