Alum

Current name

Information from the Getty AAT

alum

Colorless-to-white crystalline potassium aluminum sulfate; has a wide range of uses, including in treatment of leather and textile, in sizing paper, as a mordant in dyeing, and as a water-purifying agent.

General
Filemaker ID: 
GLO3760

From Oxford English dictionary

1. An astringent mineral salt, typically occurring as colourless or whitish crystals, that is used as a mordant for dyeing, in tanning, for sizing paper and fireproofing materials, in water purification, and in medicine (esp. as a styptic); common alum

2. Any of various substances resembling this compound in chemical properties, crystal structure, etc.; any of a series of isomorphous crystalline double sulphates of a monovalent metal or group and a trivalent metal, analogous to common or potash alum. Frequently with distinguishing word.

Other names: 
Alaun, Allaun, Allat, alat Alandt Alavn Alawn
Historical names