Mohs scale

1812 Mohs scale

The book of science

Tom Sharp

Friedrich Mohs geology Mohs scale

Mohs scale

Other hardness scales

Cheese scale

“How can you govern a country that has two hundred and forty-six varieties of cheese?” —Charles de Gaulle

I have known about the Mohs scale since college, but have never before been introduced to other hardness scales and measuring devices. Here is where common knowledge diverges from technical knowledge. Reading about hardness testing technology affirms my feeling that spending a modest amount of time studying a subject can qualify a normal person as an expert.

See also in The book of science:

Readings on wikipedia: