syenite

A geologist examines a piece of syenite in the field.

Definition

1. Noun (Geology):
   • A granular igneous rock: "syenite" is a type of intrusive igneous rock that is composed primarily of alkali feldspar, with little or no quartz. It is similar to granite but contains less quartz, often appearing in shades of gray, pink, or green.

Usage Examples

• (The rock type forming the mountain's interior.)
• (Specimens of the rock for analysis.)
• (The rock was employed in construction due to its strength.)

Advanced Usage

• "syenite porphyry": a variety of syenite containing larger crystals (phenocrysts) embedded in a finer-grained matrix.

  • The quarry exposed a layer of syenite porphyry with visible feldspar crystals. (A specific textural variant of the rock.)

• "nepheline syenite": a type of syenite that contains the mineral nepheline instead of quartz, often used in ceramics and glassmaking.

  • Nepheline syenite is valued in industry for its high alumina content. (A subtype of syenite with commercial applications.)

Variants and Related Words

• Syenitic (adj): relating to or characteristic of syenite.

  • The syenitic texture of the rock indicates slow cooling beneath the Earth's surface. (Pertaining to the rock type.)

• Syenitoid (n): a rock resembling syenite but not strictly classified as such.

  • This sample is a syenitoid, lacking the exact mineral proportions of true syenite. (A similar but distinct rock.)

Synonyms

• Granitoid: a general term for coarse-grained igneous rocks similar to granite, which can include syenite.
• Felsic rock: a category of light-colored igneous rocks, of which syenite is a member.

Related Idioms