Pyroxene

Pyroxene is a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. They are known for their significant role in the formation of the Earth's crust and mantle. Pyroxenes have a monoclinic or orthorhombic crystal structure and are composed of single chains of silica tetrahedra.

Chemical Composition

Pyroxenes are generally composed of combinations of magnesium, iron, calcium, sodium, and aluminum, along with silicon and oxygen. The general chemical formula for pyroxene is (Ca,Na)(Mg,Fe,Al)(Si,Al)₂O₆.

Physical Properties

Pyroxene minerals typically exhibit a prismatic or columnar crystal habit with two cleavage directions at approximately 90 degrees. They have a hardness ranging from 5 to 7 on the Mohs scale and can occur in various colors such as black, green, brown, or white.

Common Types

Some common types of pyroxene include augite, diopside, enstatite, and hypersthene. Each type has its own distinct chemical composition and physical properties, contributing to their unique characteristics and geological significance.

Geological Importance

Pyroxenes are crucial in understanding the formation and evolution of igneous and metamorphic rocks. Their presence and composition provide valuable insights into the conditions under which these rocks were formed, as well as the processes involved in their alteration over time.

Study Guide

When studying pyroxene, consider the following key points:

1. Learn the chemical composition and crystal structure of pyroxene.
2. Understand the physical properties and common types of pyroxene minerals.
3. Explore the geological importance of pyroxenes in the context of rock formation and Earth's history.
4. Examine the role of pyroxene in petrology, geochemistry, and geochronology studies.
5. Practice identifying pyroxene minerals through visual observation and optical properties.

By mastering these aspects of pyroxene, you will develop a solid understanding of its significance in the field of geology and earth sciences.

[Pyroxene] Related Worksheets and Study Guides:

• Minerals IIEarth Science • High School