While its mineral name is halite, this substance is also commonly known as rock salt. Rock salt is composed of sodium chloride, an essential compound the human body uses to absorb nutrients and maintain blood pressure.

Fluorite (also called fluorspar) is the crystal form of the inorganic compound calcium fluoride. The term "fluorescence," a type of luminescence by a substance that has absorbed light or radiation, is derived from this…

Collection of 13 Aramith Bakelite billiard balls. Some billiard numbers are missing or duplicated.

Green cardboard box with removable top; interior of box bottom has a white plastic insert with round indentations for…

Celestine is a mineral with a light blue color. It is a source of the element strontium (atomic symbol Sr). Strontium compounds are commonly used in fireworks, fluorescent lights, and dyes and paints.

Calcite is one of the most widely used minerals. It is primarily composed of the chemical compound calcium carbonate. Calcite is also often used in demonstrations of double refraction, in which light is split into two…

Barium (atomic symbol Ba) is an alkaline Earth metal. Barite (also spelled baryte) is a mineral composed of barium sulfate. It is used in paints, inks, paper, and rubber. It is also used in radiology for diagnostic…

Amazonite is a potassium-based blue-green variety of microcline feldspar. Its color may be an indication of the presence of iron or lead. Amazonite has been used as a decorative gemstone in statues and jewelry.