Olivine

Definition

Olivine is a magnesium iron silicate mineral that is commonly found in igneous and metamorphic rocks. It plays a significant role in the classification of Earth materials due to its composition and occurrence in various rock types, particularly in mantle-derived rocks like peridotite and basalt.

5 Must Know Facts For Your Next Test

1. Olivine is typically green in color, ranging from yellow-green to olive green, which is characteristic of its iron and magnesium content.
2. It forms under high-temperature conditions, making it a common mineral in mafic and ultramafic rocks.
3. Olivine is part of the silicate mineral group and has a unique orthorhombic crystal structure.
4. This mineral is significant in petrology as it indicates the temperature and pressure conditions of rock formation.
5. In addition to its geological importance, olivine has potential applications in carbon capture and storage due to its ability to sequester carbon dioxide.

Review Questions

• How does the composition of olivine affect its classification as a mineral and its occurrence in various rock types?
  • Olivine's classification as a mineral is influenced by its unique composition of magnesium and iron silicates. The presence of both forsterite (magnesium-rich) and fayalite (iron-rich) allows olivine to exist in different rock types, particularly those formed under high-temperature conditions. Its occurrence in igneous rocks like basalt and peridotite demonstrates how compositional variations can reflect specific geological environments and processes.
• Discuss the significance of olivine's crystal structure in relation to its physical properties and stability at varying temperatures.
  • Olivine's orthorhombic crystal structure contributes significantly to its physical properties, including hardness and cleavage. This structure allows olivine to be stable at high temperatures, making it a common component in mafic and ultramafic rocks. Understanding how this structure behaves under different thermal conditions helps geologists interpret the formation environment of igneous rocks and assess the stability of minerals within those contexts.
• Evaluate the potential role of olivine in environmental remediation strategies, particularly regarding carbon sequestration.
  • Olivine has gained attention for its potential role in environmental remediation, particularly through carbon sequestration processes. When exposed to carbon dioxide, olivine can react to form stable carbonate minerals, effectively locking away CO2 from the atmosphere. This capability makes olivine a candidate for large-scale carbon capture strategies, offering a natural solution to mitigate climate change while also enhancing our understanding of mineral stability under changing environmental conditions.

Related terms

Fayalite: A variety of olivine that is rich in iron, specifically Fe2SiO4, often found in igneous rocks and metamorphic environments.

Forsterite: The magnesium-rich end member of the olivine solid solution series, represented by Mg2SiO4, which is stable at higher temperatures.

Silicate:

A large class of minerals that include silicate tetrahedra as their building blocks, forming the most abundant group of minerals in the Earth's crust.