What is Friedelite?
Friedelite is a manganese-rich chlorite-group silicate, generally found as pink to brown platy aggregates in manganese-bearing metamorphic rocks.
Mineralogy and structure
Reference formula: Mn8Si6O15(OH)10Cl2. Friedelite has a layered monoclinic structure and a composition that can show substitutions within the chlorite group. Thin plates and cleavage are more diagnostic than colour alone.
Colour and appearance
Typical colours include pink, rose, brown, red-brown. The usual platy, foliated, massive habit and vitreous, pearly lustre are useful descriptive features, but colour alone is not diagnostic.
Formation and localities
Friedelite forms in or is associated with manganese-rich metamorphic rocks, ore deposits and altered silicate assemblages. Important documented localities include the United States, Germany, Japan, South Africa, Brazil and India.
Collecting and care
Protect platy aggregates from cleavage and abrasion; preserve the matrix and locality for a reliable identification.
Friedelite and layered texture
The layered habit of Friedelite gives it a natural visual language of sheets, surfaces and gradual change. Collectors may use those ideas in display or design, but they remain metaphors rather than mineralogical claims.
Traditional associations
Friedelite is not a recognised birthstone. Any zodiac link found in popular crystal writing varies between traditions and should be labelled non-scientific.
