Physical Properties of Iridium and Cobalt
Melting Point
1,495.00 °C
  
29
Boiling Point
4,527.00 °C
  
10
2,870.00 °C
  
34
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Gray
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Brinell Hardness
1,670.00 MPa
  
5
Vickers Hardness
1,760.00 MPa
  
3
1,043.00 MPa
  
11
Speed of Sound
4,825.00 m/s
  
13
4,720.00 m/s
  
14
Optical Properties
  
  
Allotropes
No
  
Yes
  
α Allotropes
Not Available
  
α-Cobalt
  
β Allotropes
Not Available
  
β-Cobalt
  
γ Allotropes
Not Available
  
Not Available