Let geometric style create interesting shine in your designs with the onyx 12mm faceted square beads from Dakota Stones. Available by the strand, these square beads feature diamond-shaped facets cut into the surface for hints of glinting shine at every angle. Onyx is a variety of chalcedony that is similar to agate, with straight rather than curved bands. Nearly all black onyx on the market has been rendered a uniform, permanent black color with a treatment by sugar and acid or heat. This process has been used on onyx for thousands of years and does not decrease the value of the stone. Mined in Brazil, India and Madagascar, onyx is said to set one's mind to a task. Showcase these bold beads in a necklace design for unforgettable style.