Most distinguishing features:Identified by hardness and good cleavage.
Industrial/economical uses:Modern use is in gypsum wallboard used in construction. Used as an ornamental stone and for sculpture due to its softness.
Most distinguishing features:High specific gravity is best indicator, colour and fracture are also helpful.
Industrial/economical uses:Primary ore for barium, also used as an additive to drilling mud (because of high SG). Has over 2000 uses in industry.
Most distinguishing features:Single large crystals of gypsum, typified by hardness and transparency.
Industrial/economical uses:Used in gypsum wallboard.