what are rocks?
A naturally occurring solid mixture of one or more minerals or organic matter
three types of rocks
igneous, sedimentary, metamorphic
How are rocks classified?
how they form, texture, grain size, mineral composition
intrusive igneous rock
rock formed from the cooling and solidification of magma beneath Earth's surface. cools slowly
extrusive igneous rock
rock that forms from the cooling and solidification of lava at Earth's surface. cools quickly
Examples of intrusive igneous rocks
granite, diorite, gabbro
Examples of extrusive igneous rocks
pumice, obsidian, basalt
IGNEOUS: Intrusive
Takes longer to cool, giving minerals crystals more time to grow
IGNEOUS: Extrusive
Cools quickly with little to no crystals (Fine grained)
Obsidian
a dark-coloured volcanic glass that forms from the very rapid cooling of molten rock material. It cost so rapidly that crystals do not form
Characteristics of Igneous Rocks
hard and strong interlocking crystals
Common mineral that are within Igneous Rocks
oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium
Important Igneous Rocks
Granite, Basalt, Pumice, Scoria, Obsidian
Mineral
a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition