Iolite – Overview
Intro
Iolite is valued for its inky blue-to-violet body colour and strong pleochroism, which makes orientation important in cutting.
Overview
This starter entry positions iolite as an educational gem where pleochroism, cut orientation, and tone all matter to the final face-up result.
About
This starter entry positions iolite as an educational gem where pleochroism, cut orientation, and tone all matter to the final face-up result. Iolite is presented here as a structured gemstone record ready for linked buyer guides, research posts, and media galleries.
Key Properties
| Mineral / material | Cordierite |
|---|---|
| Chemistry | Mg2Al4Si5O18 |
| Crystal system | Orthorhombic |
| Colour | Blue to violet with noticeable pleochroism |
| Refractive index | 1.542 – 1.578 |
| Birefringence | 0.008 – 0.016 |
| Specific gravity | 2.58 – 2.66 |
| Mohs hardness | 7 – 7.5 |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Toughness | Good |