Small pieces of rare Jet Fossilised Wood, from monkey puzzle trees, found in Whitby Yorkshire. Whitby Jet is a semi precious organic gemstone formed over millions of years from the fossilised remains of the modern day Monkey Puzzle, and similar trees. It is smooth and lightweight and can be polished to a deep black lustre that could be used as a mirror. The term 'jet black' meaning as dark a black as possible derives from the black colour of Whitby Jet. Age: 185 million years old These are small pieces, ideal size for jewellery making. Price is for a 30g Batch. Examples of 30g batches are shown in the photos.