The North Yorkshire Gemstone Coast.
Famous for spectacular scenery and holiday destinations, the ‘North Yorkshire and Cleveland Heritage Coast’ is as a 36 mile stretch of coast from Saltburn, just north of the National Park, down to Scalby Mills near Scarborough. The ‘accessible’ source of Jet is generally restricted to just 7.5 miles of this coastline, of which Whitby lies in the centre.
The most popular locations for collecting material - due to their proximity to the deposits - are Whitby, Staithes and Runswick Bay, with each beach and cove in-between having its own conditions as to when new material can be thrown up.
The deposits from which jet is eroded are formed in narrow seams within the cliffs, compacted between layers of shale. Due to the severe conditions of its formation – as detailed in What is Whitby Jet – and the sheer weight and pressure it has been under for millions of years, any seam of jet never exceed a depth of 30mm – 40mm. Whilst the seams can often be seen exposed on an eroded cliff face, many deposits of Whitby Jet run through the cliff, inland and continue under the North Yorkshire Moors. In the Victorian era – see History of Whitby Jet - jet was mined both inland from the moors and along the coast.