Onyx
Onyx is a bold, sophisticated gemstone prized for its deep, opaque black colour. One of the oldest known gemstones used in jewellery, onyx has been carved, polished, and worn for over 4,000 years and continues to be a staple of modern fine jewellery.
Quick Facts
Colour
Predominantly solid black (usually dyed).
Hardness
6.
Origins
Found worldwide.
Lustre
Waxy to vitreous lustre.
What is Onyx?
Onyx is a variety of chalcedony (microcrystalline quartz) characterised by parallel bands of colour. While pure black onyx is the most well-known form, onyx naturally occurs in banded patterns of black and white, or other colour combinations. Most solid black onyx available today is dyed chalcedony, as naturally occurring pure black onyx is uncommon. The dyeing process is stable and has been practiced since ancient Roman times. Sardonyx, a variety with red-brown and white bands, is also classified as onyx.
Properties
Colour
Predominantly solid black (usually dyed). Natural onyx shows parallel bands of black and white. Sardonyx displays alternating red-brown and white bands. Green onyx and blue onyx also exist but are less common.
Hardness
6.5 to 7 on the Mohs scale. Durable enough for all types of jewellery with reasonable care.
Origins
Found worldwide. Major sources include Brazil, India, Madagascar, Uruguay, and the United States. India is the largest processor and exporter of onyx.
Lustre
Waxy to vitreous lustre. When polished, onyx achieves a smooth, glossy surface. The opaque black variety has a particularly elegant, mirror-like finish.
Varieties
Black onyx is the most popular variety, offering a uniform, deep black surface. Sardonyx features alternating bands of red-brown (sard) and white onyx, prized since antiquity for cameo carving. Banded onyx displays black and white layers and is used in both carved and polished jewellery. Carnelian onyx combines red-orange carnelian layers with white. Niccolo onyx has a very thin translucent upper layer that allows the black base to show through as a dark blue-grey.
History
The word onyx comes from the Greek "onux," meaning fingernail — legend says the goddess Venus was sleeping when Cupid clipped her fingernails, and the gods turned the clippings into stone so that no part of her would perish. Ancient Romans carved onyx into cameos and intaglios. In Victorian mourning jewellery, black onyx was one of the most important materials. Art Deco designers favoured the bold contrast of black onyx with diamonds and white metal. The stone has maintained its association with sophistication and power throughout history.
Meaning & Symbolism
Onyx symbolises strength, protection, self-discipline, and focus. It has been used as a protective amulet across cultures, believed to absorb and transform negative energy. Black onyx is associated with grounding, confidence, and decision-making. In many traditions, it is considered a stone of inner strength that helps the wearer face challenges with determination.
How to Care for Onyx
Clean onyx with warm soapy water and a soft cloth. Avoid ultrasonic and steam cleaners, as the dye treatment can be affected. Protect from harsh chemicals, acids, and prolonged exposure to strong sunlight. Store separately from harder gemstones. Onyx is durable enough for rings, cufflinks, earrings, and pendants with normal care.
Onyx Jewellery Ideas
Black onyx creates striking contrast when paired with diamonds in cocktail rings, earrings, and pendants. Onyx signet rings are a classic, gender-neutral design. Art Deco-inspired jewellery frequently uses onyx and diamond combinations. Onyx beaded bracelets and necklaces are popular in both men's and women's jewellery. For a modern look, onyx set in yellow gold creates a bold, graphic aesthetic. Onyx and pearl combinations offer an elegant study in contrast.