Physical Properties of Cobalt and Hafnium
Melting Point
1,495.00 °C
  
29
2,150.00 °C
  
10
Boiling Point
2,870.00 °C
  
34
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Gray
  
Gray
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Brinell Hardness
1,450.00 MPa
  
6
Vickers Hardness
1,043.00 MPa
  
11
1,520.00 MPa
  
5
Speed of Sound
4,720.00 m/s
  
14
3,010.00 m/s
  
27
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
Yes
  
No
  
α Allotropes
α-Cobalt
  
Not Available
  
β Allotropes
β-Cobalt
  
Not Available
  
γ Allotropes
Not Available
  
Not Available