黑色或灰色结晶。能吸收水分而成水合物，但无固定组成。易被碳、一氧化碳或氢还原成钴。900℃以上时失去氧成为一氧化钴，在较低温时能吸收氧，结晶的结构不变。溶于酸和碱，几乎不溶于水。
密度：6.11
熔点:895 °C    
 

99.9% metals basis:


外观Appearance                          Black or Dark Grey 
Powder and/or Chunks 
X-射线衍射分析X-Ray Diffraction         Conforms to Structure
纯度Purity                              ≥99.9% Based on Trace Metals Impurities of ICP
Complexometric EDTA (% Co)              72.0 - 74.0 %  
ICP:                                    Confirms Cobalt Component Confirmed 
痕量金属分析total metallic impurities   ≤1000ppm by ICP Atomic emission
            

99.99% metals basis:


外观Appearance                          Black or Dark Grey 
Powder and/or Chunks 
X-射线衍射分析X-Ray Diffraction         Conforms to Structure
纯度Purity                              ≥99.99% Based on Trace Metals Impurities of ICP
Complexometric EDTA (% Co)              72.0 - 74.0 %  
ICP:                                    Confirms Cobalt Component Confirmed 
痕量金属分析total metallic impurities   ≤100ppm by ICP Atomic emission


30nm 球形，99.5%
外观Appearance                           Black powder
X射线衍射X-Ray Diffraction               Conforms to Structure
EDTA滴定Complexometric EDTA (% Co)       71.6 - 75.2 %
粒径Particle Size                        ≤30 nm
痕量金属Trace Metal Analysis             ≤5000 ppm
纯度Purity(Based on Trace Metals of ICP) ≥99.5 %

主要用于电池材料、磁性材料、热敏电阻等； 也可用作催化剂机制作珐琅等    
密封保存