Explore our collection of beautiful black onyx gemstones available from stock in a vast array of shapes and sizes. Onyx is a variety of layered Chalcedony belonging to the quartz mineral family. Its opaque appearance and dense colour makes it a striking choice when set with sparkling diamonds in pieces of jewellery. Banded onyx has visible layers of black and white chalcedony often with brown undertones cut and polished into cabochon stones or beads. Onyx was widely incorporated in Victorian and Art Deco design and is still popular in the modern day. At TOD Jewels we stock a range of onyx gemstones from buff top single facet gems, unique geometric shapes to banded cabochon loose onyx stones. Whether you are looking to engrave a family crest to set in a traditional signet ring, searching for drilled pieces with a concave centre to set diamonds we have unusual onyx piece to suit a vast range of requirements.