My+Rocks

Rock Families


 * There are three rock families:
 * #1 Igneous
 * #2 Sedimentary
 * #3 Metamorphic


 * **#1 Igneous Rock** – “Born of Fire”

Igneous rock forms from melted rock (lava or magma) when it cools


 * __Lava__** – melted rock that is found outside (“on”) the Earth’s crust

When lava and magma cool ,they form two different kinds of igneous rock: __Intrusive__ rock igneous E__x__trusive rock- igneous rock that is formed from cooled lava (e.g. pumice) When lava and magma cool, they form two different kinds of Igneous rock: 1. **__Intrusive rock__** – igneous rock that is formed from cooled magma (e.g. granite) 2. **__Extrusive rock__** – igneous rock that is formed from cooled lava (e.g. pumice, basalt, rhyolite)
 * __Magma__** – melted rock that is found inside the Earth’s crust
 * The main difference between intrusive and extrusive rock is their crystal size, which depends on how quickly they cool.
 * **__Extrusive rock__** (from lava) cools quickly and forms small crystals.
 * **__Intrusive rock__** (from magma) cools very slowly inside the Earth’s crust and forms large crystals

Sedimentary Rock

These rock layers are (called beds). As these layers of sediment slowly plié on top of each other they become tightly packed or cemented together to form rock. These on the beds push layers below and create enough pressure to form sedimentary rock – compaction. Or, as dripping water coats the sediment with dissolved minerals and cement the pieces together – cementation. E.g. mudstone (shale), sandstone limestone, and conglomerate

Metamorphic Rock Rock that has changed form into a new type of rock. The original rock ( parent rock ) is changed by pressure and heat is form a new metamorphic rock. Parent Rock Metamorphic Rock Granite Gneiss Sandstone Quartzite Mudstone Slate Limestone Marble