Jet (Black) is a type of lignite, a precursor to coal, formed from decaying plant material under high pressure and temperature over millions of years. It is known for its deep black color and smooth texture, making it a popular material for jewelry and decorative items. This gemstone has been used since ancient times, often associated with protection and grounding. Jet can be polished to a high shine and is lightweight, making it easy to wear. It is commonly found in regions like Whitby in England, where it has been mined for centuries.