Also known as Gagatù, this is a fossilized form of bituminous wood which has not yet been silicified. It is very soft and easy to carve and was extensively worked in factories in the late 1800s especially in England and Germany. Today, most material is mined in Russia and Mongolia and it has made a resurgence in the fashion market. In the late 19th Century it was a popular accessory with the black clothing worn by the women of that time. Its origins go back to the Bronze Age (necklaces and bracelets containing jets have been found with other valuables in ancient burial sites). When burnt, it gives off a vile odour and is known as the Stone of Saturn. Black symbolizes resilience, self-control and preservation and is meant to dispel fearful thoughts and to protect the wearer against illness, disease and violence.