Haematin

Haematin (also known as hematin, ferriheme, hematosin, hydroxyhemin, oxyheme, phenodin, or oxyhemochromogen) is a dark bluish or brownish pigment containing iron in the ferric state, obtained by the oxidation of haem. This is not to be confused with haematein, which is a dark purple water-insoluble crystalline substance obtained from logwood and used as an indicator and biological stain.