Definition

1. Noun:
   • A type of igneous rock: Pegmatite is a form of igneous rock characterized by its extremely coarse-grained texture, resulting from the slow crystallization of magma that is rich in rare elements and volatile substances like water and fluorine.

Usage

• Pegmatite is a geological term used to describe a specific, often visually striking, rock type. It is primarily used in academic, scientific, and industrial contexts related to geology, mineralogy, and mining.
• Example: "The geologist identified the large, interlocking crystals of feldspar and quartz as a clear sign of pegmatite."
• Example: "This mine is famous for producing gem-quality tourmaline from its pegmatite veins."

Advanced Usage

• Economic Importance: Pegmatites are often discussed for their economic value as they are a primary source for many rare-earth elements, lithium, and gemstones like tourmaline, beryl (including emerald and aquamarine), and topaz.
  • Example: "The search for new lithium deposits has focused on pegmatite formations in the region."
• Petrogenesis: In advanced geological study, pegmatite is analyzed to understand the final stages of magma crystallization and the processes of extreme fractional crystallization.
  • Example: "The pegmatite dike is interpreted as the crystallized remnant of the last, highly differentiated portion of the magma."

Variants and Related Words

• Pegmatitic (adjective): Describing the texture or nature of pegmatite.
  • Example: "The sample showed a pegmatitic texture with crystals over several centimeters in length."

Synonyms

• Coarse-grained igneous rock: A general descriptive synonym, though it is less specific than "pegmatite."
• Granitic pegmatite: A more specific term often used when the pegmatite has a mineral composition similar to granite (feldspar, quartz, mica).

Different Meanings

• The term "pegmatite" has a single, specific meaning in geology and does not have other common definitions or homonyms.

Noun

1. a form of igneous rock consisting of extremely coarse granite resulting from the crystallization of magma rich in rare elements