2. What are minerals?  Think about the last time you walked on dirt.

3. What are minerals?  Think about the last time you walked on dirt.  What color was it?

4. What are minerals?  Think about the last time you walked on dirt.  What color was it?  You have learned that Earth’s crust is made of minerals and rocks.

5. Minerals  A mineral is a solid, inorganic, natural material with a certain structure and composition.

6. Minerals  A mineral is a solid, inorganic, natural material with a certain structure and composition.  Minerals are the same throughout their composition.

7. Minerals Characteristics  Minerals are solid.

8. Minerals Characteristics  Minerals are solid.  Minerals are inorganic. This means that they were never alive or part of anything that was alive.  Graphite is made of carbon but was never alive.

9. Minerals Characteristics  Minerals are solid.  Minerals are inorganic. This means that they were never alive or part of anything that was alive.  Graphite is made of carbon but was never alive.  Minerals form in nature.

10. Minerals Characteristics  Minerals are solid.  Minerals are inorganic. This means that they were never alive or part of anything that was alive.  Graphite is made of carbon but was never alive.  Minerals form in nature.  Minerals have a specific chemical make-up, or composition.  For example, the formula for halite (table salt) is NaCl. So one molecule of halite is always made of one atom of sodium (Na) and one atom of chlorine (Cl).

11. Minerals Characteristics  Minerals have a definite structure. A mineral’s structure depends on the atoms that make up the mineral and how the atoms combine.  Diamond and graphite are both made only of carbon (C). However, the carbon atoms in diamond are arranged in a different structure than the carbon atoms in graphite.

12. Minerals Not all minerals can be identified by color. However, some minerals, such as sulfur, have characteristic colors. What other properties of sulfur can you see in this picture?

13. Minerals Not all minerals can be identified by color. However, some minerals, such as sulfur, have characteristic colors. What other properties of sulfur can you see in this picture? Luster, Shininess, Cleavage, Clean Sides

14. Minerals: Properties of Minerals  Each type of mineral has certain characteristics or properties.

15. Minerals: Properties of Minerals  Each type of mineral has certain characteristics or properties.  Different properties are the result of the chemical compositions and physical structure of each mineral.

16. Minerals: Properties of Minerals  Color is likely the first property that you might observe.

17. Minerals: Properties of Minerals  Color is likely the first property that you might observe.  Some minerals are always the same color, such as gold.

18. Minerals: Properties of Minerals  Luster is a property that describes the way a mineral reflects light.

19. Minerals: Properties of Minerals  Luster is a property that describes the way a mineral reflects light.  A mineral with metallic luster is shiny, like a polished metal.  Silver and pyrite have metallic luster.

20. Minerals: Properties of Minerals  Luster is a property that describes the way a mineral reflects light.  Nonmetallic minerals do not have a shiny luster.

21. Minerals: Properties of Minerals  Luster is a property that describes the way a mineral reflects light.  Nonmetallic minerals do not have a shiny luster.  The surface of talc resembles the surface of a pearl, so talc’s luster is described as pearly.

22. Minerals: Properties of Minerals  Luster is a property that describes the way a mineral reflects light.  Quartz has a glassy luster.

23. Minerals: Properties of Minerals  Luster is a property that describes the way a mineral reflects light.  Quartz has a glassy luster.  Because one form of the mineral hematite looks like an earthen clay pot, its luster is described as earthy.

24. Minerals: Properties of Minerals  Streak is the color of a mineral in its powdered form.

25. Minerals: Properties of Minerals  Streak is the color of a mineral in its powdered form.  A streak test is done by dragging a mineral across an unglazed, porcelain title called a streak plate.

26. Minerals: Properties of Minerals  Streak is the color of a mineral in its powdered form.  A streak test is done by dragging a mineral across an unglazed, porcelain title called a streak plate.  This causes the part of the mineral being dragged to break down into a powder.

27. Minerals: Properties of Minerals  Streak is the color of a mineral in its powdered form.  Minerals with metallic luster produce dark-colored streaks.

28. Minerals: Properties of Minerals  Streak is the color of a mineral in its powdered form.  Minerals with metallic luster produce dark-colored streaks.  Minerals with nonmetallic luster are usually produce either colorless or very light streaks.

29. Minerals: Properties of Minerals  Streak is the color of a mineral in its powdered form.  Minerals with metallic luster produce dark-colored streaks.  Minerals with nonmetallic luster are usually produce either colorless or very light streaks.  Minerals that are harder than the streak plate show no streak at all.

30. Properties of Minerals: Hardness  Another mineral property is hardness.

31. Properties of Minerals: Hardness  Another mineral property is hardness.  Hardness is the resistance of a mineral to being scratched.

32. Properties of Minerals: Hardness  Another mineral property is hardness.  Hardness is the resistance of a mineral to being scratched.  A mineralogist named Friedrich Mohs developed a scale that ranks the hardness of certain minerals.

33. Properties of Minerals: Hardness Minerals and objects with higher numbers on the scale will scratch minerals and objects with lower numbers on the scale.

34. Properties of Minerals: Cleavage & Fracture  Atoms are arranged differently in different minerals.

35. Properties of Minerals: Cleavage & Fracture  Atoms are arranged differently in different minerals.  These arrangements cause minerals to break in different ways.

36. Properties of Minerals: Cleavage & Fracture  Minerals that break along smooth planes have cleavage.

37. Properties of Minerals: Cleavage & Fracture  Minerals that break along smooth planes have cleavage.  Graphite is a mineral that has cleavage in only one direction.

38. Properties of Minerals: Cleavage & Fracture  Minerals that break along smooth planes have cleavage.  Graphite is a mineral that has cleavage in only one direction.  This causes it to cleave, or break, into thin sheets.

39. Properties of Minerals: Cleavage & Fracture  Minerals that break along smooth planes have cleavage.  Graphite is a mineral that has cleavage in only one direction.  This causes it to cleave, or break, into thin sheets.  Minerals that break along rough, uneven surfaces have fracture.

40. Properties of Minerals: Cleavage & Fracture  Minerals that break along smooth planes have cleavage.  Graphite is a mineral that has cleavage in only one direction.  This causes it to cleave, or break, into thin sheets.  Minerals that break along rough, uneven surfaces have fracture.  Quartz is one mineral that fractures.

41. Properties of Minerals Other Properties  In addition to color, luster, streak, hardness, and cleavage or fracture, many minerals have unique properties.

42. Properties of Minerals Other Properties  In addition to color, luster, streak, hardness, and cleavage or fracture, many minerals have unique properties.  The mineral magnetite, for example, is magnetic.

43. Properties of Minerals Other Properties  In addition to color, luster, streak, hardness, and cleavage or fracture, many minerals have unique properties.  The mineral magnetite, for example, is magnetic.  Halite tastes salty.

44. Properties of Minerals Other Properties  In addition to color, luster, streak, hardness, and cleavage or fracture, many minerals have unique properties.  The mineral magnetite, for example, is magnetic.  Halite tastes salty.  Gold does not rust.

45. Properties of Minerals: Other Properties  The mineral calcite has several unique properties.  It fuzzes when it contacts an acid.  It also has a property called double refraction, which causes light shining through it to split into two rays.