- Color: strongly pleochroic, reddish brown, pink / yellowish green
- Hardness: 7 - 7.5
- Refractive index: 1.63 - 1.65
- Density: 3.13 - 3.21
- Chemical composition: Al2SiO5
- Crystal structure: orthorhombic
- Lustre: vitreous, greasy
- Origins: Spain, Brazil, USA, Sri Lanka, Burma.
Discovered in Andalusia (Spain), the andalusite stone is relatively rare, with big crystals over 10 ct. especially rare. Due to its remarkable pleochroism effect, the stone is highly valued by collectors.