Octagon Buff Top Single Bevel Genuine Black Onyx

Black onyx, also known as black agate, is dyed black chalcedony — one of the most enduring and versatile gem materials in the jeweler's palette. Chalcedony is composed of microscopic quartz crystals invisible to the naked eye. Natural black chalcedony is exceptionally rare; as a result, all black chalcedony on the market is grey chalcedony that has been chemically treated to achieve its signature deep, uniform black color. Black onyx remains the top-selling chalcedony in the trade and carries a rich history in jewelry design, most notably as a staple of the Art Deco movement.

These octagon buff top cabochons feature a single bevel cut and a polished, opaque black surface that photographs beautifully and pairs well with both white and yellow metals. Ideal for rings, pendants, brooches, and earrings across a range of jewelry styles.

Clean with warm, soapy water. Use of ultrasonic and steam cleaners is generally considered safe for this material.

Features

• Genuine black onyx (dyed black chalcedony)
• Octagon buff top with single bevel profile
• Uniform opaque black color throughout
• Smooth, polished cabochon surface
• Treatment: Dyed — industry-standard process for all black chalcedony
• Historically significant gem material associated with Art Deco jewelry design
• Safe for ultrasonic and steam cleaning

Specifications

Available Options