Onyx is a variety of chalcedony or microcrystalline quartz which is formed in the gas cavities of lava. Generally, most onyx has a parallel banding structure (as opposed to agate which is more irregular), however black onyx doesn’t tend to have this characteristic banding.
As a healing stone, black onyx is thought to increase regeneration, happiness, intuition and instincts.
Tumbled stones offer a learning and discovery tool, they are unique heartfelt gifts and work as home accents in fountains, vases, candle displays and plants. If you are selecting them for special meditation and healing practices.