Igneous rocks are recognized by:
- the interlocking texture of the grains
- the presence of vesicules (holes) in extrusive igneous rocks
- may be dark-colored and heavy
- may display two grain sizes, one much larger than the other
Sedimentary rocks are recognized by:
- grains cemented together
- the presence of fossils
- light-colored and light weight
- may display interlocking grains but is very light weight
Metamorphic rocks are recognized by:
- the interlocking texture of large grains
- foliation (layering)
- banded light and dark colors
- “ching” sound instead of a “chunk” sound when tapped