erythrite

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A reddish secondary cobalt mineral, CO₃(AsO₄)₂·8H₂O, found in veins bearing cobalt and arsenic and used in coloring glass.

from The Century Dictionary.

• noun A hydrous arseniate of cobalt, of a rose-red color, occurring in radiated or acicular crystalline forms and as a pulverulent incrustation. Also called cobalt-bloom and erythrin.
• noun A rose-red variety of orthoclase feldspar from amygdaloid near Kilpatrick, Scotland.
• noun A crystalline organic principle (C₄H₆(OH)₄) obtained from several species of lichens by extraction with milk of lime.

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

• noun (Chem.) A colorless crystalline substance, C4H6.(OH)4, of a sweet, cooling taste, extracted from certain lichens, and obtained by the decomposition of erythrin; -- called also erythrol, erythroglucin, erythromannite, pseudorcin, cobalt bloom, and under the name phycite obtained from the alga Protococcus vulgaris. It is a tetrabasic alcohol, corresponding to glycol and glycerin.
• noun (Min.) A rose-red mineral, crystallized and earthy, a hydrous arseniate of cobalt, known also as cobalt bloom; -- called also erythrin or erythrine.

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

• noun mineralogy Red cobalt, a secondary hydrated arsenate of cobalt minerals with the formula (Co3(AsO4)2·8H2O).

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a reddish mineral consisting of hydrated cobalt arsenate in monoclinic crystalline form and used in coloring glass; usually found in veins bearing cobalt and arsenic