Vocabulary #9

1.Mineral: A solid material of earth"s crust with a definite composition.

2.Luster: The way light bounces off a mineral"s surface.

3.streak:  The color of the powder left when a mineral is rubbed against a hard,roygh surface

4.Hardness: How well a mineral resists scratching.

5.Cleavage: The tendency of a mineral to break along flat surfaces.

6.Ore: A mineral containing a useful substance.

7. Gem: A mineral containing a useful substance.

8.Nonrenewable resource: A resource that cannot be replaced within a short period of time or at all.