Gypsum

Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO₄·2H₂O. It is widely used in construction as a material for making plaster and drywall. Gypsum is also used in agriculture as a soil conditioner and fertilizer. It is found in nature as the mineral selenite and also in its crystalline form as alabaster.

Properties of Gypsum

Hardness: 2 on the Mohs scale
Color: Colorless to white, yellow, red, brown, and gray
Luster: Vitreous to silky
Transparency: Transparent to translucent

Formation and Occurrence

Gypsum is formed as an evaporite mineral, meaning it is deposited from the evaporation of water. It is commonly found in sedimentary rock formations and is often associated with halite, anhydrite, and sulfur deposits. Gypsum can be found in large evaporite beds, particularly in the United States, Canada, and Mexico.

Uses of Gypsum

Gypsum has a wide range of uses, including:

Construction: Gypsum is a key ingredient in plaster, drywall, and cement. It is used to create durable and fire-resistant building materials.
Agriculture: Gypsum is used as a soil amendment to improve the structure and fertility of soil. It provides calcium and sulfur, essential nutrients for plant growth.
Medical: Gypsum is used in medicine for making plaster casts to immobilize broken bones during the healing process.

Study Guide Questions

What is the chemical formula of gypsum?
What is the hardness of gypsum on the Mohs scale?
Where is gypsum commonly found in nature?
What are the main uses of gypsum?

◂Earth Science Worksheets and Study Guides High School. Rocks I

Vocabulary/Answer key

Rocks I

Vocabulary/Answer key

Rocks I

Vocabulary/Answer key

Rocks I

The resources above cover the following skills:

EARTH AND SPACE SCIENCE

Earth’s Systems

Construct an explanation from evidence for the processes that generate the transformation of rocks in Earth’s crust, including chemical composition of minerals and characteristics of sedimentary, igneous, and metamorphic rocks.

ENVIRONMENTAL SCIENCE

Earth and Human Activity

Engage in argument from evidence to defend how coastal, marine, and freshwater sources (e.g., estuaries, marshes, tidal pools, wetlands, beaches, inlets, rivers, lakes, oceans, coral reefs) support biodiversity, economic stability, and human recreation.