Definition

1. Noun:
   • A laminated metamorphic rock similar to granite: Gneiss is a type of coarse-grained, high-grade metamorphic rock characterized by its banded or foliated appearance, resulting from the segregation of different minerals into distinct light and dark layers. It is typically composed of minerals like feldspar, quartz, and mica.

Usage Examples

• Noun:
  • The mountain's core is composed of ancient gneiss.
  • Geologists study the banding in gneiss to understand the region's tectonic history.

Advanced Usage

• "Gneissic" (adjective): Pertaining to or having the characteristics of gneiss.
  • The outcrop displayed a pronounced gneissic texture.

Variants and Related Words

• Orthogneiss: Gneiss derived from the metamorphism of an igneous rock.
• Paragneiss: Gneiss derived from the metamorphism of a sedimentary rock.
• Migmatite: A rock that is a mixture of igneous and metamorphic components, often transitional to gneiss.

Synonyms

• Metamorphic rock (a broader category)
• Banded rock (descriptive)

Related Phrases and Terms

• Gneiss dome: A geological structure where gneiss forms a dome-shaped uplift.
• Banded gneiss: A common descriptive term emphasizing the rock's layered appearance.

Noun

1. a laminated metamorphic rock similar to granite