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Jet

Fossilised monkey puzzle wood from the Yorkshire coast, black and very light.

Early Jurassic (Toarcian). · Moderate to find

What is it?

Jet is a hard, black, lightweight material formed from the compressed wood of araucarian trees buried in the Lower Jurassic mudstones of the Yorkshire coast. It was worked at Whitby into jewellery through the nineteenth century and is still collected from the foreshore.

What does it look like?

Deep matt black, noticeably light for its size, with a slightly warm feel. It takes a high polish and shows a brown streak when rubbed on unglazed ceramic.

How to identify it

  1. 01Jet is far lighter than coal or shale of the same size.
  2. 02It gives a brown streak; coal gives a black one.
  3. 03Collect loose pieces from the foreshore. Digging jet from the cliffs is not acceptable and the cliffs are unstable.

Where to find jet in the UK

Regions

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