Minerals are naturally occurring solid substances with specific chemical compositions and atomic structures, while rocks are aggregates of one or more minerals. There are three main types of rocks: sedimentary rocks, which form from the accumulation of sediment; igneous rocks, which form from the cooling of magma; and metamorphic rocks, which form from the alteration of existing rocks by heat and pressure in the earth's crust. Common examples of each rock type are listed.

1. Minerals and RocksAn introduction to Geology:Mineralogy and Petrology

2. MineralsA mineral is a naturally occurring solid with a specific chemical composition and atomic arrangement (crystalline structure).*Quartz = Silica + Oxygen or SiO2* Some references also add “inorganic” to the definition, but there are some rare organic minerals too (i.e., whewillite).

3. Methods to Identify MineralsColorStreakLusterFluorescenceChemical CompositionHardnessTalcGypsumCalciteFluoriteApatiteOrthoclaseQuartzTopazCorundumDiamond( Mnemonic Devise - The Geologist Can Find An Ordinary Quartz Tourists Call Diamond)Specific GravityCrystal FormOptical PropertiesCleavageFractureMagnetismElectrical PropertiesMelting PointGeologic Setting

4. Copper

5. Gold

6. Pyrite (Fool’s Gold)

7. Arsenic

8. Bauxite (aluminum ore)

9. Kaolin Mine Near Thomson, Georgia

10. Barite (rose morphology)

11. Quartz

12. ROCKS A rock is any naturally occurring solid mass of mineral or minerals.

13. There are three primary types of rocks:SedimentaryIgneousMetamorphic

14. SEDIMENTARY ROCKSRocks formed from accumulation and hardening of water or airborne sediment, plant or animal remains, chemical action, or evaporation.Some of the most common sedimentary rocks are:Limestone

15. Shale

16. Sandstone Limestone

17. Limestone with fossils

18. Shale

19. Sandstone

20. PeatCoal

21. Igneous Rocks Igneous rocks are formed by the cooling of magma from deep within the earth

22. There are two main categories of igneous rocks:Intrusive – formed undergroundExtrusive – formed above ground

23. The most common intrusive igneous rock is granite.Some common extrusive igneous rocks include: Basalt

24. Obsidian

25. PumiceGranite with thin-section

26. ← Obsidian Pumice ->

27. Basalt – vesicular (with holes), dense, and thin-section

28. Metamorphic RocksThese rocks are formed by other rocks being buried deep within the earth and subjected to very high temperature and pressure.Common metamorphic rocks include: Marble

29. Greenstone

30. Slate

31. Schist

32. GneissMarble with thin section

33. Greenstone

34. Slate with Pyrite ↓ ↑Slate (plain)

35. Gneiss

36. Schist – highly folded