phonolite
Noun: - A fine-grained volcanic rock: "phonolite" is a type of igneous rock, typically light-colored and composed mainly of feldspar and feldspathoid minerals, often containing small crystals. It is known for ringing when struck, hence its name derived from the Greek word for "sound stone."
- (A volcanic rock that produces a sound when hit.)
- (A practical application of the rock.)
"Phonolite lava flow": a geological formation where phonolite magma has erupted and solidified.
- The ancient phonolite lava flow created a distinctive landscape in the region. (A hardened volcanic deposit.)
"Phonolite porphyry": a variety of phonolite with larger crystals embedded in a fine-grained matrix.
- The phonolite porphyry sample showed prominent feldspar crystals. (A specific textural type of the rock.)
Phonolitic (adj): relating to or resembling phonolite.
- The phonolitic texture of the rock indicates a slow cooling process. (Describing the rock's characteristics.)
Phonolite tuff (n): a volcanic rock formed from compacted ash and fragments of phonolite.
- The phonolite tuff deposits are rich in mineral content. (A pyroclastic rock type.)
Clinkstone: an older term for phonolite, referring to its ringing property.
- The clinkstone outcrop was easily recognizable by its metallic sound. (A synonym emphasizing the acoustic quality.)
Trachyte: a similar fine-grained volcanic rock, though with different mineral composition.
- Trachyte and phonolite are often confused in field identification. (A related rock type.)