pallasite

Thân thiện

A polished slice of pallasite reveals beautiful green olivine crystals set in a metallic matrix.

Definition

Noun: 1. A type of stony-iron meteorite: A pallasite is a specific class of meteorite characterized by a distinctive composition and structure. It consists primarily of large, gem-quality crystals of the mineral olivine (a yellow-green silicate) embedded within a continuous network of metallic iron-nickel alloy.

Usage

• Pallasites are among the rarest and most visually striking meteorites.
• Scientists study pallasites to understand the differentiation and formation of planetary bodies in the early solar system.
• The olivine crystals in a pallasite are sometimes referred to as "peridot," which is the gemstone variety.

Examples

• The museum's new acquisition is a magnificent pallasite slab showing brilliant green olivine set in a silvery metal matrix.
• Analysis confirmed that the recovered fragment was a pallasite, not a more common iron or stony meteorite.
• Pallasites are believed to originate from the boundary layer between the core and mantle of a differentiated asteroid that was shattered by impacts.

Advanced Usage

• Pallasitic: The adjective form used to describe the texture, composition, or origin related to pallasites.
  • The sample exhibits a pallasitic texture, indicative of its formation at a core-mantle boundary.

Variants and Related Words

• Pallasitic (adjective): Of or relating to pallasites.
• Mesosiderite (noun): Another major class of stony-iron meteorite, distinct from pallasites as it contains silicate rock fragments mixed with metal, rather than olivine crystals.
• Olivine (noun): The magnesium-iron silicate mineral that forms the characteristic crystals in pallasites.
• Peridot (noun): The gem-quality variety of olivine found in some pallasites.

Synonyms

• Stony-iron meteorite (This is the broader class; "pallasite" is a specific type within this class.)

Notes

• The name "pallasite" is derived from the German naturalist Peter Simon Pallas, who described the first known specimen, the meteorite, found in Russia in 1749.
• Pallasites hold significant importance in planetary science as they are thought to be samples from the deep interiors of protoplanets.

Học thuật

Noun

1. a meteorite composed principally of olivine and metallic iron