This product is a lot of 100% natural black onyx square cut calibrated loose gemstones, ranging in size from 5mm to 20mm. Handmade in India, these gemstones are of excellent quality and are crafted with precision. The black onyx stones are of natural origin and are faceted cut to bring out their beauty. Perfect for jewelry making or for adding a touch of luxury to any project, these gemstones are sure to elevate any design with their sleek square shape and black color.