The hardest natural mineral in the world is lonsdaleite, a rare mineral made of carbon atoms. This mineral can withstand up to 58 percent more stress than diamond, according to a report by Jessica Griggs of NewScientist.
Lonsdaleite is very rare, which makes it difficult for scientists to gather samples for experiments. The mineral forms when graphite-containing meteorites come into contact with Earth. Lonsdaleite is similar to diamond, which was previously the hardest natural mineral known to man, but its carbon atoms are arranged in a different way. Despite its hardness, lonsdaleite may not be as useful as the second hardest natural mineral, wurtzite boron nitride, which withstands up to 18 more stress than diamond. This is because the wurtzite boron nitride is stable at higher temperatures.