noun
- plural of rhyolite; fine-grained volcanic rocks that are rich in silica and typically light-colored
Usage: geology
Examples
- The geologist collected samples of rhyolites from the ancient volcanic field.
- These rhyolites formed when silica-rich magma cooled rapidly at the surface.
- The mountain range contains extensive deposits of rhyolites and other volcanic rocks.
- Students examined thin sections of rhyolites under the microscope.
- The light-colored rhyolites contrasted sharply with the darker basalts.
- Rhyolites often contain small crystals of quartz and feldspar.