Are these diamonds?

[Curran]

i have been told a simple test is if u have a 10x loupe rub the smoothest surface across your forhead and look at it with the loupe the diamond being carbon and your sweat having a significant amount of carbon in it means if its a diamond your sweat will spread accross the surface if its not then your sweat will bead up like tiny droplets

[Capt. Mendoza]

  when I first read this I thought you were saying to look at your forehead with a loupe...    I suppose this method works best the further north you go.