<unk>  is an organic compound with the formula C6H3(OH)3.  It is a white solid although because of its sensitivity toward oxygen, samples are typically brownish.  It is one of three isomeric benzenetriols.
Pyrogallol
Dichloroacetic acid
Azelaic acid
Pyritinol
Methenamine hippurate
2,4-Dichlorobenzyl alcohol
Phosphoric acid
Gitoformate