1. Chapter 5 : Igneous Rocks 5.2 – Classifying Igneous Rocks

2. 1) Mineral Composition: The 3 main groups of igneous rocks are grouped by the minerals that they contain. The 3 main groups of igneous rocks are grouped by the minerals that they contain. 1) Felsic 1) Felsic 2) Mafic 2) Mafic 3) Intermediate 3) Intermediate

3. 2) Grain Size Due to either fast or slow cooling. Due to either fast or slow cooling. Slow = Big grains/crystals Slow = Big grains/crystals Fast = Small grains/crystals Fast = Small grains/crystals WHICH IS WHICH?

4. 3) Texture The size and shape of the crystals in the rock. The size and shape of the crystals in the rock.

5. Igneous Rocks as Resources: The interlocking grains in igneous rocks make the rocks very strong. The interlocking grains in igneous rocks make the rocks very strong. Uses: Uses: Kitchen tiles/counters Kitchen tiles/counters Architecture (ex: columns) Architecture (ex: columns) Vietnam Memorial in Washington, D.C. Vietnam Memorial in Washington, D.C.

7. Ore Deposits: Igneous rocks can contain veins with valuable elements. Igneous rocks can contain veins with valuable elements. Ex: gold, silver, copper, lithium, and beryllium Ex: gold, silver, copper, lithium, and beryllium

8. Diamonds – found in igneous rocks called kimberlites (named after Kimberly, South Africa) Diamonds – found in igneous rocks called kimberlites (named after Kimberly, South Africa)

9. These form deep in the crust at 150-300 km or in the mantle. These form deep in the crust at 150-300 km or in the mantle. Diamonds can only form under high pressures. Diamonds can only form under high pressures. Most of the world’s diamonds come from South African mines. Most of the world’s diamonds come from South African mines.

10. The Kimberly Diamond mine was dug over a period of 48 years (1866-1914) and yielded 2,722 kg of diamonds. The Kimberly Diamond mine was dug over a period of 48 years (1866-1914) and yielded 2,722 kg of diamonds.