It may surprise many people to learn that Whitby Jet started out as a tree around 180 million years ago. The tree was the predominant species in the mid Jurassic period and it’s closest relation today is the Monkey Puzzle tree!
The Monkey Puzzle trees were washed down rivers into the sea becoming water logged in the process. This meant they slowly sank down to the sea bed along with other washed out vegetation and silt was formed. Over time this layer of silt (sedimentary layer) built up creating huge amounts of pressure on the now decaying trunks. This pressure caused anaerobic fossilisation to occur which compacted the trees cells down and forced certain other elements into the trunks.
The extremely high pressure also caused the trunks to compact and flatten out creating seams of Jet in the surrounding shale which is made up of other vegetation which has undergone the same process.
There are two types of Whitby Jet, hard Jet and Soft Jet. Hard Jet was formed in salt water and soft Jet in fresh water. The main difference between these two types is hard Jet is very high quality and soft Jet is poor quality and does not get the stunning Jet black gleam once polished.
*Here at Jet Black Amber we only use the highest grade Whitby Jet.
Finding Whitby Jet
Whitby Jet can be found along a seven mile stretch of the North Yorkshire coastline.
To visit this area of coastline looking for fossils and not come back with any would be virtually impossible. They really are everywhere especially Ammonites and Bellamites….! These can be found in a number of different ways from cracking open a likely looking nodule, to picking them up from the shale.
You will also come across countless fossilised shells and other sea plant life.