chert
/tʃɜrt/
noun
- A hard, dark, or light-colored sedimentary rock made of very fine quartz crystals, often found in layers or nodules in limestone.
- The old stone wall was built with chunks of chert mixed with other local rocks.
- Geologists study chert to understand the ancient ocean environments where it formed.
- The hiker picked up a piece of chert that had a sharp edge, perfect for making a tool.
Synonyms