1. A hard, fine-grained sedimentary rock, typically brown or gray, composed of silica and resembling flint or chert.
Usage: geology; also called hornfels in metamorphic contexts

Examples

• The geologist identified the specimen as hornstone based on its hardness and siliceous composition.
• Hornstone was used by ancient peoples to make tools and weapons.
• The quarry produced large blocks of hornstone suitable for construction.
• Hornstone deposits are often found in sedimentary rock formations.
• The artifact was carved from a piece of hornstone that had been naturally weathered smooth.