How would you determine if a mineral was gypsum?

Answer 1

Gypsum is one of the softest of minerals. It is only 1.5 on the scale of hardness and can be cut with a knife. Gypsum's specific gravity is 2.2 and it weighs 135 pounds per square foot. It does not melt under a blowpipe and does not react to Hydrochloric acid. It often accompanies rock salt or halite and frequently contains Sulfur beds and may or may not be transparent.

Answer 2

To determine if a mineral is gypsum, you can perform a scratch test by scratching the mineral with a fingernail or a knife. Gypsum has a hardness of 2 on the Mohs scale, so it should be easily scratched. Additionally, gypsum can be identified by its white color, pearly luster, and tendency to form "blades" or "roses" in its crystal structure. Finally, you can also perform a chemical test by applying a drop of dilute hydrochloric acid to see if it effervesces, as gypsum will react with acid.