Calcite

Calcite has been found in over 2,500 distinct shapes. No one is quite sure why there are so many varieties of calcite, but impurities, temperature and composition during growth all may create variations on basic shapes. There are three basic shapes: trigonal prism, scalenohedron, and rhombohedron. The crystals shown here are referred to as triple dogtooth, a grouping of thick scalenohedral crystals that are double pyramid in form. The point of the scalenohedron is sharp and resembles the canine tooth of a dog, hence the name.

Calcite

Calcite has been found in over 2,500 distinct shapes. No one is quite sure why there are so many varieties of calcite, but impurities, temperature and composition during growth all may create variations on basic shapes. There are three basic shapes: trigonal prism, scalenohedron, and rhombohedron. The crystals shown here are hexagonal tabular crystals.

Calcite

Calcite has been found in over 2,500 distinct shapes. No one is quite sure why there are so many varieties of calcite, but impurities, temperature and composition during growth all may create variations on basic shapes. There are three basic shapes: trigonal prism, scalenohedron, and rhombohedron. The crystals shown here are rhombohedron.

Calcite

This calcite is a forced twin crystal.

Calcite

Calcite has been found in over 2,500 distinct shapes. No one is quite sure why there are so many varieties of calcite, but impurities, temperature and composition during growth all may create variations on basic shapes. There are three basic shapes: trigonal prism, scalenohedron, and rhombohedron. The crystals shown here are scalenohedron.

Calcite

Calcite

Calcite crystalline stalactite "brush". Calcite has been found in over 2,500 distinct shapes. No one is quite sure why there are so many varieties of calcite, but impurities, temperature and composition during growth all may create variations on basic shapes. There are three basic shapes: trigonal prism, scalenohedron, and rhombohedron.

Calcite

Pure calcite, which has a chemical composition of CaCO3, is white. The pink color of this specimen is caused by impurities of manganese.

Calcite

Calcite has been found in over 2,500 distinct shapes. No one is quite sure why there are so many varieties of calcite, but impurities, temperature and composition during growth all may create variations on basic shapes. There are three basic shapes: trigonal prism, scalenohedron, and rhombohedron.

Calcite

Calcite has been found in over 2,500 distinct shapes. No one is quite sure why there are so many varieties of calcite, but impurities, temperature and composition during growth all may create variations on basic shapes. There are three basic shapes: trigonal prism, scalenohedron, and rhombohedron.

Calcite (on Quartz)

This specimen grew in two stages. First, amethyst crystals formed in an underground cavity from water containing dissolved silica. Later, another solution entered the cavity and formed the calcite crystals on top.

Calcite Spires

Calcite has been found in over 2,500 distinct shapes. No one is quite sure why there are so many varieties of calcite, but impurities, temperature and composition during growth all may create variations on basic shapes. There are three basic shapes: trigonal prism, scalenohedron, and rhombohedron.

Calcite Stalagmites

These small stalactites are composed of tiny calcite crystals that grew as water containing dissolved minerals dripped from the roof of a cave.

Calcite with goethite

Millions of microscopic calcite crystals make up these stalactites, colored red by goethite. As they grew in a small cavity in limestone, a change in conditions resulted in a second generation of large, blocky calcite crystals.

Calcite with sphalerite and fluorite

The football-shaped mineral is calcite - here two large, twinned crystals. The black crystals are sphalerite, a source of zinc; the purple crystals are fluorite. Rarely do large crystals, such as these, survive the mining process.