Olivine

Definition

Olivine is a common silicate mineral found in the Earth's crust and mantle, as well as in the Moon and other planetary bodies. It is a magnesium-iron silicate with the chemical formula (Mg,Fe)2SiO4, and is an important component in the composition of the lunar surface and the planet Mercury.

5 Must Know Facts For Your Next Test

1. Olivine is a major component of the lunar mantle, contributing to the dark coloration of the lunar maria.
2. The presence of olivine on the lunar surface is evidence of the Moon's differentiation, with the denser olivine-rich material sinking to form the lunar mantle.
3. Olivine is also a significant mineral in the composition of Mercury's surface, reflecting the planet's geologic history and similarity to the Moon.
4. The abundance of olivine on the lunar surface and in Mercury's crust is a result of the high-temperature, reducing conditions that prevailed during the formation of these bodies.
5. Olivine's resistance to weathering and its distinctive green color make it a useful indicator mineral for identifying the composition and origin of planetary surfaces.

Review Questions

• Explain the significance of olivine in the context of the general properties of the Moon.
  • Olivine is a key component of the lunar mantle, contributing to the dark coloration of the lunar maria. The presence of olivine on the lunar surface is evidence of the Moon's differentiation, with the denser olivine-rich material sinking to form the lunar mantle. This indicates that the Moon underwent high-temperature, reducing conditions during its formation, similar to the conditions that formed the Earth's mantle.
• Describe the role of olivine in the composition and features of the lunar surface.
  • Olivine, along with pyroxene, is a major constituent of the lunar crust and mantle. The abundance of olivine in the lunar highlands, which are composed primarily of anorthositic rocks, reflects the high-temperature, reducing conditions that prevailed during the Moon's formation. The dark coloration of the lunar maria is also attributed to the presence of olivine-rich basalts. The resistance of olivine to weathering and its distinctive green color make it a useful indicator mineral for identifying the composition and origin of the lunar surface.
• Compare and contrast the significance of olivine in the context of the Moon and Mercury.
  • Olivine is a significant mineral in the composition of both the lunar surface and the surface of Mercury. On the Moon, olivine is a major component of the lunar mantle and contributes to the dark coloration of the lunar maria, reflecting the Moon's differentiation and high-temperature, reducing formation conditions. Similarly, the presence of olivine on Mercury's surface is also a result of the planet's geologic history and similarity to the Moon, with both bodies sharing a common origin and experiencing comparable high-temperature, reducing conditions during their formation. The abundance of olivine on these planetary surfaces provides important clues about their composition, origin, and evolution.

Related terms

Basalt:

A type of dark, fine-grained igneous rock that is rich in olivine and pyroxene minerals, commonly found in the lunar maria and on the surface of Mercury.

Pyroxene:

A group of silicate minerals that, along with olivine, are major constituents of the lunar and Mercurian crusts and mantles.

Lunar Highlands: The heavily cratered, light-colored regions of the Moon's surface that are composed primarily of anorthositic rocks, with lesser amounts of olivine and pyroxene.