Pigments through the Ages - Technical Information

About the chemical structure:

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

Color:

Color Index (C.I.)

PG 19

How can you identify Cobalt green?

Imaging:

OM: Cobalt green appears as fine, rounded and transparent particles under the microscope.

Analytics:

It's identified by means of Raman

Raman spectra: University College London;

Usage and handling:

Permanence:	Toxicity:
Lightfast: good Degradation processes: most sources considered it to be absolutely permanent as most pigments produced at high temperatures are. However, tests made in 1847 and published in 1910 showed a browning of the color in full-strength and a fading of it when mixed with lead white. Artists did not favor cobalt green although it could safely be mixed with all other pigments and was a fast drier in oil. Field called it, "chemically good and artistically bad"	non toxic. MSDS: Holbein

Permanence:

Toxicity:

Lightfast: good

Degradation processes: most sources considered it to be absolutely permanent as most pigments produced at high temperatures are. However, tests made in 1847 and published in 1910 showed a browning of the color in full-strength and a fading of it when mixed with lead white. Artists did not favor cobalt green although it could safely be mixed with all other pigments and was a fast drier in oil. Field called it, "chemically good and artistically bad"

non toxic.

MSDS: Holbein