2.  A mineral that most living things need- you can find this in milk or cheese

4.  A resistance of a material or metal to scratching or breaking

6.  The way the light reflects from the surface of a mineral

8.  A shiny, dense substance that easily conducts heat and electricity

10.  A natural, solid substance found in rocks

12.  minerals in rock that can be extracted and used by people to make things

14.  The color of a mineral in a powered form

16.  a type of rock that forms when melted rock cools and hardens

18.  one of the major types of rock that is created from previously existing rock by the action of intense heat and pressure

20.  a type of rock formed by gravity pressing fragments of other rocks and minerals together as they settle on land or under the ocean over a long period of time