A market-wide average across qualities and sizes. Your stone's value depends on carat, color, clarity, cut, treatment, and origin.
Cordierite, marketed as iolite in the gem trade, is a magnesium aluminum silicate known for strong pleochroism, appearing violet-blue from one direction and yellowish or gray from another. With Mohs hardness 7–7.5 and reasonable toughness, it can be used in most jewelry types with appropriate protection.
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.
The GemstoneAI market index for iolite is $45 per carat as of 2026-08-04. 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.
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.
Over the past 30 days the iolite index moved -5.2%. Gem prices move on supply, demand, and metal markets; treat any single stone as a collectible first and an asset second.