• Webster's Revised Unabridged Dictionary
    • n Alunogen (Min) A white fibrous mineral frequently found on the walls of mines and quarries, chiefly hydrous sulphate of alumina; -- also called feather alum, and hair salt.
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Century Dictionary and Cyclopedia
    • n alunogen Native aluminium sulphate, occurring in fine capillary fibers, and consisting of 36.05 parts of sulphuric acid, 15.40 of alumina, and 48.55 of water. It is found in volcanic solfataras, in clays, in feldspathic rocks containing pyrites, and as an efflorescence on the walls of mines and quarries. Also called hair-salt and feather-alum.
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Webster's Revised Unabridged Dictionary
F. alun, alum + -gen,