Botryoidal, green Emmonsite on Limonite
CHEMISTRY - Fe2Te3O9.2H2O
CRYSTALLOGRAPHY - Triclinic
CRYSTAL GROWTH AND HABITS - Typically as fibrous crusts or as a radially acicular growth; also as scaly druses.
COLOR AND OPTICAL PROPERTIES - Light pale yellow to greenish yellow.
HARDNESS - 5
SPECIFIC GRAVITY - 4.5
LUSTER - Vitreous
STREAK - White
BREAKABILITY - Very good cleavage {010}
OCCURRENCE - Emmonsite is a secondary mineral formed by the weathering of Tellurium bearing minerals.
ASSOCIATED MINERALS - Cerussite, Mackayite, Blakeite
MINERAL NAME - Named after Samuel F. Emmons, an economic geologist for the United States Geological Survey.