通常 white or colorless; colorless transparent crystals are known as alabaster. Sometimes it is gray, light yellow, light brown, etc., due to impurities. Streaks are white. Transparent. Glassy luster;珍珠like luster on cleavage planes; silky luster in fibrous aggregates.

The cleavage is perfect and moderate, with cleavage planes forming a rhombus with angles of 66 and 114 degrees. It is brittle. Hardness ranges from 1.5 to 2. There is slight variation in different directions. Relative density is 2.3. Gypsum powder is one of the five main gel materials, holding an important position in the national economy. It is widely used in construction, building materials, industrial molds and artistic models, chemical industry, agriculture, and many other application fields, making it a significant industrial raw material.