ESAY+4.3

=**Vocabulary**=


 * Gemstone:** A hard colorful mixture that has a brilliant or glassy luster
 * Ore:** A rock that contains a metal or economically useful mineral
 * Alloy:** A combination of two or more metals

=**Outline**=

Minerals are a source of metals, gemstones, and other materials used to make products.

 * Gemstones such as rubies and sapphires are valued for their color, luster and durability and because they are rare.
 * Metals such as aluminum, iron, copper or silver are useful because they can be stretched into wire, or flattened into sheets, and hammered or molded without breaking.


 * Ores**
 * A rock containing a useful mineral is called an ore.
 * Most metals do not come in a pure form.
 * A metal usually occurs as a mineral that isa combination of metal and other elements.
 * Prospecting**
 * A prospector is anyone who searches or prospects for an ore deposit.
 * Geologists prospect for ores by looking for certain features on the earth's surface.


 * Mining**
 * There are three types of mines. They are strip mines, open pit mines and shaft mines.
 * In strip mining earth moving equipment scrapes away soil to expose ore
 * In open pit mining ,miners use earthmoving equipment to dig an tremendous pit
 * Miners dig an open pit mine to remove ore deposits that may start near the surface ,but extend down for hundreds of meters.
 * some open pit miners are more than a kilometer wide and nearly


 * Smelting**
 * After miners remove ore from the mine, smelting is necessary to remove the metal from the ore.
 * In this process of smelting, an ore is melted to separate the useful metal from other elements the ore contains.[[image:ronald.jpg]]