<span><span>Minerals are homogeneous, naturally occurring, inorganic solids. Each mineral has a definite chemical composition and a characteristic crystalline structure. A mineral may be a single element such as copper (Cu) or gold (Au), or it may be a compound made up of a number of elements. About 2,500 different minerals have been described.</span><span>Rocks are made up of one or more minerals.</span></span>THERE ARE THREE TYPES OF ROCKS. THEY ARE:<span>1. <span>Igneous Rocks </span>: Formed from the cooling of molten rock.<span>A. Volcanic igneous rocks formed from molten rock that cooled quickly on or near the earth's surface.
B. Plutonic igneous rocks are the result of the slow cooling of molten rock far beneath the surface.</span>2. <span>Sedimentary Rocks </span>: Formed in layers as the result of moderate pressure on accumulated sediments.
3. <span>Metamorphic Rocks </span>: Formed from older "parent" rock (either igneous or sedimentary) under intense heat and/or pressure at considerable depths beneath the earth's surface.</span><span>THE INTERRELATIONSHIP AMONG THE ROCK TYPES IS REFERRED TO AS THE
ROCK CYCLE</span>.THERE ARE FOUR MAIN LAYERS THAT MAKE UP THE EARTH:
<span>1.<span> Inner Core </span>- A mass of iron with a temperature of about 7000 degrees F. Although such temperatures would normally melt iron, immense pressure on it keeps it in a solid form. The inner core is approximately 1,500 miles in diameter.
2.<span> Outer Core </span>- A mass of molten iron about 1,425 miles deep that surrounds the solid inner core. Electrical currents generated from this area produce the earth's magnetic field.
3.<span> Mantle </span>- A rock layer about 1,750 miles thick that reaches about half the distance to the center of the earth. parts of this layer become hot enough to liquify and become slow moving molten rock or magma.
4.<span> Crust </span>- A layer from 4-25 miles thick consisting of sand and rock. hope i helped</span>
