Mohs Hardness Scale

By Educational Resources 2021 (approx.)

This image shows ten minerals from soft to hard and common tools used to test the hardness of each mineral.

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Detailed Description

The Mohs Scale of Mineral Hardness (created by Friedrich Mohs in 1822)

https://pubs.usgs.gov/gip/gemstones/mineral.html 

Sources/Usage

Public Domain.