Onyx Value & Market Price
A market-wide average across qualities and sizes. Your stone's value depends on carat, color, clarity, cut, treatment, and origin.
About onyx
Onyx is a striking banded variety of chalcedony, known for its rich black color often accented with white or brown bands. It has a hardness of 6.5 to 7 on the Mohs scale, making it suitable for various jewelry applications, commonly cut into cabochons or beads.
Where onyx comes from
- Brazil (~30% of supply)
- India (~25% of supply)
- Uruguay (~20% of supply)
- Madagascar (~12% of supply)
What is your onyx worth?
Market averages will not price your stone. GemstoneAI identifies gems and jewelry from a photo, checks authenticity and treatment signals, and gives you a real market valuation in seconds. Free to try.
How much is onyx worth?
The GemstoneAI market index for onyx is $5.00 per carat as of 2026-08-17. That is a market-wide average across qualities, not a quote for a specific stone. Individual value depends on carat, color, clarity, cut, treatment, and origin.
How can I tell if my onyx is real?
Visual tests alone are unreliable. GemstoneAI analyzes a photo of your stone for identity, treatment indicators, and authenticity signals, then estimates market value. It is free to try.
Is onyx a good investment?
Over the past 30 days the onyx index moved +0.0%. Gem prices move on supply, demand, and metal markets; treat any single stone as a collectible first and an asset second.