- Color: red, orange, yellow, brown, bi-color brown to greenish
- Hardness: 6.5
- Refractive index: 1.53 - 1.55
- Density: 2.54 - 2.63
- Chemical composition: complex aluminosilicate
- Crystal structure: triclinic
- Origins: Canada, USA, Tanzania.
Considered to be a collector's stone, this is a variety of feldspar (plagioclase), with intense red and orange crystals being the most valued. Diffuse inclusions produce the distinctive shimmering effect known as schiller, which does not reduce the value of the stone.