Onyx is a banded variety of the silicate mineral chalcedony or a layered calcite/aragonite stone, famed for its parallel color bands and deep jet-black varieties used widely in jewelry, carvings, and architecture.Key Characteristics & TypesComposition: Scientifically a microcrystalline quartz (chalcedony), though decorative architectural "onyx" is often banded calcite.Hardness: Scores 6.5 to 7 on the Mohs scale, making it durable enough for rings, pendants, and bracelets.Colors: True or treated black onyx is most common, but natural variants feature bands of white, red, brown (sardonyx), or green.Treatments: Most commercial black onyx on the market is treated or dyed to achieve a uniform, solid dark color, as natural stones often feature white or grey striping.History & SymbolismAncient Uses: Used by ancient Egyptians for protective amulets and by Greeks and Romans for intaglios and cameos.Victorian Era: Popularized extensively as official mourning jewelry during the reign of Queen Victoria.Metaphysical Beliefs: Widely regarded as a stone of inner strength, grounding, and protection against negative energies.If you are looking to buy or work with onyx, let me know if you are interested in:Jewelry and care tipsMetaphysical propertiesArchitectural or interior uses