Definition

1. Noun:
   • A very acid volcanic rock: Rhyolite is a type of igneous, volcanic rock with a high silica (acidic) content. It is typically light in color, often pink or gray, and has a fine-grained texture, though it can sometimes contain glass or larger crystals.

Usage Examples

• Noun:
  • The geologist identified the sample as rhyolite due to its high quartz content and fine-grained texture.
  • Yellowstone National Park features dramatic landscapes formed from ancient rhyolite lava flows.

Advanced Usage

• Geological Context: In geology, 'rhyolite' is often discussed in contrast to other volcanic rocks like basalt, which has a lower silica content. It is the volcanic equivalent of the plutonic rock granite.
  • The volcanic field is composed primarily of rhyolite and andesite.

Variants and Related Words

• Rhyolitic (adj): Pertaining to or composed of rhyolite.
  • The rhyolitic magma is highly viscous and can lead to explosive eruptions.

Synonyms

• Acidic volcanic rock: A descriptive synonym highlighting its chemical composition.
• Felsite: A general field term for light-colored, fine-grained igneous rocks, which can include rhyolite.

Noun

1. very acid volcanic rock