Cobalt blue

/ ko • bawlt   bloo /

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About the chemical structure:

Chemical name: Cobalt(II) oxide-aluminum oxide
Formula: CoO · Al2O3
Refractive index: n/a


Color Index (C.I.) PB 28

How can you identify Cobalt blue?


UVF: blue

IRFC: red

OM: cobalt blue has coarse particles, like azurite and ultramarine, but is distinguished microscopically by their non-crystalline appearance. Particle size is usually 1-50μm

Microscopic appearance at x500 mag


It can be identified by FTIR and Raman.

Raman spectra: University College London;

FTIR spectra: IRUG;

Usage and handling:

Permanence: Toxicity:

Lightfast: excellent

Degradation processes: very stable.

non toxic.

MSDS: Winsor & Newton


Cobaltpigmente (at Pigmentlexikon by Th. Seilnacht)

Cobalt und seine Blaufarben, Neue Zürcher Zeitung, 214, 15.9.1993, p. 67