Cobalt blue
Cobalt blue is a blue pigment consisting principally of cobalt(II) aluminate, CoAl2O4, made by sintering cobalt(II) oxide with aluminium(III) oxide (alumina) at high temperatures. It is used as a ceramic color, in automotive and industrial coatings, in scientific and medical imaging, and as a fine-art pigment. Its thermostability, chemical inertness, and lightfastness make it suitable for applications requiring a durable blue color.
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