Rocksday

Willemite

A zinc silicate that glows an intense green under shortwave UV.

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

How to identify willemite

  • Dull green or brown in daylight.
  • Brilliant green glow under shortwave UV.
  • Often with red-glowing calcite and black franklinite.

Often confused with

Where it's found

  • Franklin and Sterling Hill, New Jersey
  • Arizona
  • Namibia

Uses

Zinc ore; synthetic willemite coated early TV and radar screens.

Rock tumbling

Can be tumbled with care.

Did you know?

It's named after King Willem I of the Netherlands.

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

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