Fuchsite (Green Muscovite in Quartz)

Hardness: 2-3 (Mica) to 7 (Quartz matrix), Color: Emerald green to pale sea-foam green, Luster: Pearly to vitreous, Crystal structure: Monoclinic, Cleavage: Perfect basal.

Formed through regional metamorphism of rocks containing chromium. It is often found in phyllites and schists, or as inclusions in quartzite. Generally found in Precambrian or Paleozoic geological environments.

Primarily used as an ornamental stone, for lapidary work (cabs and carvings), and as a mineral specimen for collectors. In ground form, it is occasionally used as a lubricant or in the manufacturing of decorative paints.

The vibrant green color is caused by trace amounts of trivalent chromium replacing aluminum in the crystal lattice. When it occurs as inclusions in quartzite, it is known as Aventurine. It was named after the German chemist and mineralogist Johann Nepomuk von Fuchs.

Identify in the field by its distinctive bright green 'micaceous' sparkle and flaky layers. Commonly found in Brazil, India, Zimbabwe, and Russia. For collectors, look for high-contrast green patches against white quartz or stable massive forms that won't crumble.