You searched for: “agate
1. Banded or cloudy quartz with a waxy appearance.
2. Cryptocrystalline with crystals that are too small to be seen with an optical microscope.

It contains silica that is composed of cloudy and banded chalcedony (translucent or grayish semiprecious stone), sometimes mixed with opal, which forms in rock cavities.

This entry is located in the following unit: Geology or Related Geological Terms + (page 1)