1. Igneous Rocks From lava or magma Can be either extrusive (formed on Earth’s surface, from lava) Or intrusive (formed inside of the Earth’s surface, from magma)

2. 1. Granite Intrusive (inside the Earth) Light colored High quartz content

3. 2. Gabbro Intrusive (inside the Earth) Dark colored Lower silica content

4. 3. Rhyolite Extrusive Light colored (pinkish) High quartz content

5. 4. Basalt Extrusive Dark colored Lower silica

6. 5. Felsite Extrusive Light colored (light gray or whitish) High in quartz

7. 6. Pumice Extrusive “Fluffy” rock Will float in water (until it gets water- logged)

8. 7. Obsidian Extrusive Volcanic glass Was used for arrowheads

9. Sedimentary Rocks Formed from sediment Can be either clastic (from little pieces) Chemical (settled from water) Or Organic/Biochemical (from living things)

10. 1. Conglomerate Clastic Contains larger rounded clasts (parts)

11. 2. Sandstone Clastic Contains sand-sized grains

12. 3. Shale Clastic – although it doesn’t look like it Made from mud or silt

13. 4. Rock Salt Chemical Forms from the evaporation of water from salty oceans or lakes

14. 5. Chert (or flint) Chemical Forms from the growth of silicon dioxide crystals

15. 6 & 7. Limestone Chemical or Biochemical Formed from precipitation of calcium carbonate from water (chemical) OR from the accumulation of shells, corals, and alga material

16. 8. Coal Biochemical Formed from the accumulation of plant material, usually in a swampy environment

17. Metamorphic Rocks Changed Rocks Can be either foliated or non-foliated

18. 1. Marble Non-foliated (not stripe-y) Made from limestone (calcium carbonate)

19. 2. Quartzite Non-foliated Made from sandstone (mostly quartz )

20. 3. Amphibolite Non-foliated Made of amphibole and plagioclase, very little quartz

21. 4. Slate Foliated (has “layers”…like an onion…) http://www.youtube.com/watch?v=x2m_ hwDlntw http://www.youtube.com/watch?v=x2m_ hwDlntw Made from shale

22. 5. Phyllite Foliated Made of fine grained mica Usually lustrous

23. 6. Gneiss Foliated Has lots of quartz and feldspar

24. 7. Schist Foliated Contains mica, which allows it to split often