Rocks True or False: Once an igneous rock-always an igneous rock? Once a metamorphic rock-always a metamorphic rock?- Once a sedimentary rock- always a sedimentary rock?

What is a rock? A solid, naturally occurring chunk in the lithosphere that were melted, cemented, or pressed together (may contains minerals)

What happens that changes one type to another? Igneous Rocks – **Igneous rocks are formed when magma (molten rock deep within the earth) cools and hardens. – When lava cools very quickly, no crystals form and the rock looks shiny and glasslike. – Sometimes gas bubbles are trapped in the rock during the cooling process, leaving tiny holes and spaces in the rock.

What happens that changes one type to another? Sedimentary Rocks – Sedimentary rocks are formed from particles of sand, shells, pebbles, and other fragments of material; called sediment. – Gradually, the sediment accumulates in layers and over a long period of time hardens into rock. – Generally, sedimentary rock is fairly soft and may break apart or crumble easily. You can often see sand, pebbles, or stones in the rock, and it is usually the only type that contains fossils.

What happens that changes one type to another? Metamorphic Rocks – Metamorphic rocks are formed under the surface of the earth from the metamorphosis (change) that occurs due to intense heat and pressure (squeezing).

Rock Cycle

Minerals Minerals are found in the earth or are naturally occurring substances. Minerals are chemical substances. Some minerals like gold or silver are made of only one element Fun Fact! – The elements oxygen, silicon, aluminum, iron, magnesium, calcium, potassium, and sodium make up 99 percent of all minerals on Earth.

Moh’s Scale Moh's Hardness Scale HardnessMineralDescription 1TalcFingernail scratches it easily. 2GypsumFingernail scratches it. 3CalciteCopper penny scratches it. 4FluoriteSteel knife scratches it easily. 5ApatiteSteel knife scratches it. 6FeldsparSteel knife does not scratch it easily, but scratches glass. 7QuartzHardest common mineral.It scratches steel and glass easily 8TopazHarder than any common mineral. 9CorundumIt scratches Topaz. 10DiamondIt is the hardest of all minerals.