Feldspar (hardness: 6-6.5 Mohs)

Two distinctly different alkali alumino silicates: the Plagioclase and the Alkali Feldspar Series

Specific gravity: 2.55-2.76

Plagioclase Series—

Labradorite: Colorful, iridescent, also transparent stones in yellow, orange, red, and green

Sunstone: Gold spangles from inclusions of hematite

Peristerite: Blue white iridescence

Alkali Feldspar Group—

Orthoclase: Pale yellow, flesh red

Amazonite: Yellow green to greenish blue