Product Code : 4259 Stone Name : Black Onyx Shape : Pear Size : L-38 x W-29 x H-6 MM Weight : 56 Carats
The fact is, not all onyx stones are black. The onyx gemstone is a variety of chalcedony, which falls under the group of minerals called quartz. The name onyx usually refers to chalcedony of alternate bands, usually white and black. Like quartz crystals, onyx is a hard rock, rated in the Mohs scale of hardness at 6 to 7. Agate is also a kind of chalcedony that occurs in different bands of colors, not excluding black and white. How different is onyx from agate? Onyx Besides color, the only characteristic that differentiates onyx from agate is the quality of banding. If the stripes in a banded chalcedony are parallel to each other, the stone is called onyx. If the bands are chaotic, the stone is just agate. This differentiation is only artificial, however, and is not thoroughly observed. The fact is, the onyx gemstone is a variety of agate. Agate comes in a great variety of colors, but when agate occurs in black and white bands, the stone may be called onyx. In modern usage, the name onyx itself usually refers to black onyx. The use of this black onyx gemstone is traced far back in history.