Synonyms: Natural Black 1, C.I. 75920 CAS: 517-28-2 Empirical Formula: C16H14O6 · xH2O Molecular Weight: 302.28 g/mol Test Specification Appearance Fine, beige to tan to light brown powder Dye Content 60% min. Water 8.0% max. Spectroscopy As per Stains Commission Solubility in Alcohol To pass test Suitability for Microscopy To pass test