Vocabulary #13

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, rough surface.
4. hardness: how well a mineral resist scratching.
5. cleavage: the tendecy of a mineral to break along flat surface.
6. ore: a mineral containig a useful subtance
7. gem: a mineral valueed for being rare and beatiful.
8. nonrenewable resource: a resource that cannot be repleced within a short period of time or at all.