DAJB+4.3

=Vocabulary=


 * Ore**: A rock that contains a metal or an economically useful mineral.


 * Smelting:** Ore that is melted to separate the useful metal from other elements.


 * Alloy**: A solid mixture of two or more metals.


 * Gemstone:** Is a hard and colorful rock that has not yet been cut into a gem.

=Outline=


 * ==The uses of minerals==


 * **Gemstones**
 * used to make jewelry
 * valued for their color, luster and durability
 * when polished and cut is called a gem
 * **Metals**
 * Used for metal tools, machinery and money
 * can be made into wires and molded
 * **other useful minerals**
 * Salt is used or food, Quartz is used for glass, Talc is used for talcum powder, Fluorite is used for aluminum and steel.


 * ==Ores==
 * metals are usually found combined with other elements


 * ==Prospecting==
 * geologists have many ways to find valuable ore. They look at:
 * features on the surface
 * types of rocks on the surface
 * plants on the surface
 * chemicals in the streams
 * underground maps made using shockwaves
 * ==Mining==
 * Three types of mines:
 * strip mines- bulldozers take the top layers of dirt away to expose the ore
 * open pit mines- deep hole dug to find ore
 * shaft mines- tunnels deep underground that follow a vein


 * ==Smelting==
 * Ore is mixed with other materials and then heated. The metal melts and can be poured off.[[image:Smelting.JPG]]