Mineral or not? Which of these is a mineral? Why or why not? Rose Quartz Princess Penny Garnet Gene Simmons

Eggs are to cake… What minerals are to rocks.

3 Main Rock Groups Igneous Sedimentary Metamorphic

Igneous Rocks

Magma is molten rock

Igneous Rocks

2 Types of Igneous Rocks

Intrusive Igneous Rocks Intrusive or Plutonic rocks form when molten rock, or magma, is trapped deep within the earth where it slowly cools and solidifies. The cooling may take thousands or even millions of years. Since it takes so long to cool, the crystals within the rock may grow relatively large. Slow cooling, and large crystals create a coarse grained texture. ◦ Ex: granite, gabbro, diorite

Igneous Rocks Intrusive or Plutonic Batholith- large igneous intrusion Sills – an igneous intrusion parallel to the layers Lacolith – an igneous intrusion into sedimentary layers

Intrusive Igneous Rocks

Extrusive Igneous Rocks Extrusive rocks are formed by magma that exits the earth(lava). ◦ Ex: From volcanoes, and fissures. As magma erupts from the earth it cools very rapidly. There is little time to form large crystals. ◦ Extrusive rocks are fine grained or even glassy texture.  Ex: basalt, rhyolite, obsidian.

Extrusive Igneous Rocks

Igneous Rocks

Igneous Rock groups 2 main groups based on their chemical composition; Mafic Felsic

Mafic Mafic magmas have relatively low silica (Si) and high Fe and Mg contents. ◦ The high Fe and Mg content makes these rocks heavier & darker than felsic types.  Mafic magma will cool and crystallize to produce the volcanic rock basalt and gabbro.

Mafic Very Hot lava, rich in iron and magnesium, low in silica, is fluid and flows like hot tar (highly viscous). ◦ Mafic Magnesium + Iron  Mg + Fe

Mafic rocks Ma gnesium + Iron ( Fe ) More easily weathered than felsic-types Highly dense/heavy Dark colored ◦ Ex: basalt, gabbro

Felsic Felsic magmas, have relatively high silica and low Fe and Mg contents. ◦ Lighter in weight and color than mafic. ◦ Felsic magma will cool and crystallize to produce dacite and rhyolite.  Intermediate-composition magmas will crystallize to produce the rock andesite.

Felsic Cooler, gas-poor lava high in silicon, sodium, and potassium can be either pasty, blocky or flows very slowly (not viscous). ◦ FelsicFeldspar + Silicon  Fe + Si

Felsic Rocks Feldspar + Si ◦ Harder ◦ Weather last ◦ Low density ◦ Lighter color ◦ Ex: quartz, muscovite, orthoclase

Igneous Rocks If lava is felsic and contains a high percentage of gases it will be explosive. ◦ If thick the lava will explode in blocks or bombs.

Igneous Rocks If lavas are thin and contain few gases, the flow will be very viscous. ◦ Smooth, liquidy

How Igneous Rocks are formed

Extrusive Igneous Rocks

What type of igneous rocks are formed here?

vies/ What types of igneous rocks would be formed here?