Microcline (Var. Amazonite) Spheres
Morefield Mine
Amelia, Virginia

These two spheres measure 8cm and 6cm in diameter

Microcline KAlSi₃O₈

Tectosilicate; potassium aluminum silicate, sometimes with considerable amounts of sodium

Color and Luster: White, pink, brown, gray, green, colorless, yellowish; vitreous, streak white

Hardness: 6-6.5

Cleavage: Good, two directions at 90°

Fracture: Uneven

Crystals: Monoclinic or triclinic; predominantly as single crystals of rectangular or square cross section and as tabular crystals; twin crystals very common; also cleavage masses, granular, disseminated grains

Note: Orthoclase, sanadine, adularia, and microcline are the potash feldspars Andularia is often called moonstone, with a transparent or opalescent appearance Sanadine is glassy Microcline is white to pale yellow, rarely red, and when bright green it is called amazonite

Photo by Lance Kearns

Descriptions taken from
The Audubon Society Field Guide to North American Rocks and Minerals