Cobalt (II) Oxide appears as olive-green to red crystals, or greyish or black powder. Cobalt (II) Oxide is used extensively in the ceramics industry as an additive to create blue colored glazes and enamels as well as in the chemical industry for producing cobalt(II) salts.
Cobaltous Chloride (CoCl2∙6H2O in commercial form), a pink solid that changes to blue as it dehydrates, is utilized in catalyst preparation and as an indicator of humidity.