One of the methods used to measure mineral hardness, and one that is regularly used to classify gems and minerals, is the Mohs Scale. Created by Friedrich Mohs, a German geologist and mineralogist, in 1812, the Mohs Scale ranks minerals based on their scratch resistance. The more minerals that can scratch the tested mineral, the lower its number on the Mohs Scale. Conversely, harder minerals will scratch softer ones. It's common for people to confuse gemstones with minerals, but the Mohs Scale helps clarify their differences. For instance, diamonds, sapphires, and rubies are among the hardest minerals and are highly valued as gemstones.
Below, I will discuss the hardest gems and minerals found on the planet, according to the Mohs Scale. For more detailed information, you can also read our article on the differences between gemstones, rocks, and minerals