What is the hardness of gypsum?
Gypsum is a soft, lightweight mineral that is used for many purposes, including construction and insulation. It is about 2.4 times as hard as quartz and about 1.8 times as hard as marble. What is the softest mineral on Earth? The softest mineral on Earth is chalcopyrite. Chalcopyrite is a cryptocrystalline, earthy mineral that is ... Read more...