amygdules
/əˈmɪɡdulz/
noun
- Small, rounded cavities in volcanic rock that are filled with minerals such as quartz or calcite.
- The polished slab revealed colorful amygdules of agate and jasper.
- The hiker noticed tiny amygdules in the lava rock, sparkling with quartz crystals.
- Geologists study amygdules to learn about the minerals that formed after the rock cooled.