Rocksday

Celestine

Strontium sulfate, best known for pale sky-blue crystals filling geodes from Madagascar.

Celestine specimen
Photo: Ivar Leidus, CC BY-SA 4.0, via Wikimedia Commons

How to identify celestine

  • Pale sky blue, sometimes white.
  • Bladed or tabular crystals.
  • Heavy for a pale mineral.
  • Turns a flame crimson red.

Often confused with

Where it's found

  • Sakoany, Madagascar
  • Put-in-Bay, Ohio
  • Sicily

Uses

Strontium for red fireworks and flares.

Rock tumbling

Not suitable for tumbling.

Did you know?

Crystal Cave in Put-in-Bay, Ohio, is a celestine geode big enough to walk into.

Think you could spot it from a blurry close-up?

Play today's Rocksday