ANOTHER WARNING ABOUT NICKEL DUST A person who is replicating the experiment told me that after vigorous rubbing, the weight of the mesh decreased. I asked Mizuno to comment. He said that some forms of Pd are hardened, to the point where they are harder than typical Ni. If you are using one, instead of measuring the weight gain of the mesh, you should measure the decrease in weight from the Pd sample. He added, "when the palladium is harder, that means there will be a lot nickel powder, which is extremely dangerous to inhale." He provided these numbers for hardness:
Palladium Mohs hardness 4.75 Vickers hardness 461 MPa Brinell hardness 37.3 MPa Nickel Mohs hardness 4.0 Vickers hardness 638 MPa Brinell hardness 700 MPa
