A naturally occurring solid in earth's crust with a definite structure and composition.

A rock that forms when hot,liquid lava cools and hardens into a solid.

A rock that forms from pieces of other rocks that are squeezed or cemented together.

A rock that forms from another kind of rock.

Rocks continually changing from one kind into another in a never ending process.

A mixture of small particles or droplets dispersed throughout a liquid.

The age of a rock as compared with another rock.

A listing of earth's rock layers in order from oldest to youngest.

Any trace,imprint,or remains of a living thing preserved in earth's crust

The remains of a living thing that was on earth for a short period

The time it takes for half the mass of a radioactive element in a rock to break apart

The age of a rock

One of the four Long stretches of time in earth's history