alunogen

from The Century Dictionary.

• noun 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.

from the GNU version of the Collaborative International Dictionary of English.

• noun (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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mineralogy An aluminium sulfate mineral often found on the walls of mines and quarries.