Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease ... For example, diamond is only one number away, but it’s many times harder than gems in the ...

But the Mohs scale is deceptive. The steps between the minerals are not evenly spaced. For example, diamond is only one number away, but it’s many times harder than gems in the corundum family. Opal ...

The sample was cut into a gemstone weighing 1.61 carats for further studies. Kyawthuite has an asymmetrical structure and a Mohs hardness of 5.5. It formed deep underground in a pegmatite — an ...