1. Minerals The Building Blocks of Rocks

2. What are minerals made of? Most minerals are made up of a combination of two or more elements. Most minerals are made up of a combination of two or more elements. Elements such as Na, Ca, Fe, Mg, O, Si, Al, K – and others that you might recognize from the periodic table of elements combine together to form minerals. Elements such as Na, Ca, Fe, Mg, O, Si, Al, K – and others that you might recognize from the periodic table of elements combine together to form minerals.

3. Minerals All Minerals are made up of single elements or compounds. All Minerals are made up of single elements or compounds. Element: An element is made up of atoms, and cannot be broken down into a simpler substance. Compound: A compound contains 2 or more kinds of atoms that are bonded (joined) together. Atom: An atom is the smallest part of an element – it has all of the properties of the element, but cannot be seen – even with tools.

4. A naturally occurring, inorganic solid crystalline substance with a definite chemical composition. A mineral must have these 5 major aspects: If even just one of these requirements are not satisfied, then the substance is NOT a mineral. 1 Naturally Occurring 2 Inorganic 3 Solid 4 Crystal 5 Definite Chemical Composition 4000 Mineral on Earth

6. Naturally Occurring Something formed in nature, NOT MAN-MADE Something formed in nature, NOT MAN-MADE Example: Diamond, Copper, Salt Example: Diamond, Copper, Salt Minerals are a girl’s best friend! Diamond is a mineral Diamond is a mineral Cubic Zirconia is not Cubic Zirconia is not Which one is a Diamond? ×

7. Inorganic Something that was never living. Something that was never living. An inorganic substance was formed by earth processes. An inorganic substance was formed by earth processes. Is ice inorganic? Is paper inorganic? Is rock from magma inorganic? Is a dead cat inorganic? Are synthetically created substance minerals? After all, they were never alive?

8. Solid Something that has a definite, ridged shape and volume. Something that has a definite, ridged shape and volume. Gas and liquids are not minerals. Gas and liquids are not minerals. Is air a mineral? Is mercury a mineral?

9. Crystalline Substance Atoms are arranged in a orderly pattern. Atoms are arranged in a orderly pattern. Particles line up in a pattern that repeats over and over again…called a crystal Particles line up in a pattern that repeats over and over again…called a crystal A crystal has flat sides called faces. A crystal has flat sides called faces.

10. Crystalline Substance There are 7 Crystal Systems There are 7 Crystal Systems Cubic Tetragonal The cube is composed of 6 square faces at 90° angles to each other. Each face intersects one of the crystallographic axes and is parallel to the other two. The tetragonal system also has three axes that all meet at 90°. It differs from the isometric system in that the C axis is longer than the A and B axis which are the same length.

11. Crystalline Substance There are 7 Crystal Systems There are 7 Crystal Systems Hexagonal Trigonal In the hexagonal system we have an additional axes, which gives the crystals six sides. Three of these are equal in length and meet at 60° to each other. The C or vertical axis is at 90° to the shorter axes. Mineralogists sometimes divide this into two systems, the hexagonal and the trigonal, based on their external appearance, as follows: Again, the trigonal system is a subsystem of the hexagonal. Most gem references will list these as hexagonal.

12. Crystalline Substance There are 7 Crystal Systems There are 7 Crystal Systems Orthorhombic Monoclinic In this system there are three axes, all of which meet at 90° to each other. However, all the axes are a different length. The above crystal systems all have axes sides that meet at 90°. In the monoclinic system all the axes are different lengths. Two of them, the A and C axes, meet at 90°, but the third one does not.

13. Crystalline Substance There are 7 Crystal Systems There are 7 Crystal Systems Triclinic In this system all the axes are different lengths and none of them meet at 90°.

14. Definite Chemical Composition Every mineral has its own chemical composition. Every mineral has its own chemical composition. A chemical composition is like a recipe for baking. A chemical composition is like a recipe for baking. A mineral has certain elements combined in certain amounts. A mineral has certain elements combined in certain amounts. Just like baking, the ingredients must be in the right amounts for it to turn out the way the recipe intended. Na + Cl = NaCl (Salt) Si + O 2 = SiO 2 (Quartz) Si + O 2 is not the same as Si + O 3 Substance 1 1 Egg 1 cup flour 2 cups sugar Substance 2 5 Eggs 1 cup Flour 8 cups sugar

15. How do minerals form? Minerals form through processes called crystallization. Minerals form through processes called crystallization. Crystallization is a “crystal-forming process”. Crystallization is a “crystal-forming process”. Minerals are Crystals Minerals are Crystals Not all crystals are minerals! Not all crystals are minerals! Mineral (Crystals) can form in two ways 1.Cooling of Magma 2.Solution Evaporation

16. Cooling of Magma Magma is melted rock liquefied into a pool of elements. Magma is melted rock liquefied into a pool of elements. Things like Fe, Mg, Ca are all floating around in the liquid magma. Things like Fe, Mg, Ca are all floating around in the liquid magma. Just like water cooling to form ice, magma can cool so the elements in the liquid become solids. Just like water cooling to form ice, magma can cool so the elements in the liquid become solids. The elements solidify and group together to form solid crystals called minerals and fall out of the liquid magma. The elements solidify and group together to form solid crystals called minerals and fall out of the liquid magma.

17. Cooling of Magma The size of the minerals crystal depends on how fast the magma cools… The size of the minerals crystal depends on how fast the magma cools… Fast Cooling magma. Fast Cooling magma. Small Crystals Small Crystals The minerals do not have enough time to grow. The minerals do not have enough time to grow. Slow Cooling Magma Slow Cooling Magma Large Crystals Large Crystals The crystals grow larger because they have more time to grow. The crystals grow larger because they have more time to grow.

18. Cooling of Magma

19. Where would magma cool the slowest? Where would magma cool the slowest? Where would magma cool the fastest? Where would magma cool the fastest? Where would we find large crystals in minerals? Where would we find large crystals in minerals?

20. Solution Evaporation Minerals dissolve in water and create a solution. Minerals dissolve in water and create a solution. Eventually, the water will evaporate and the minerals will fall out of solution and be left behind. Eventually, the water will evaporate and the minerals will fall out of solution and be left behind. When minerals fall out of a solution they are said to precipitate. When minerals fall out of a solution they are said to precipitate. EXAMPLE: Salt Water evaporating with salt crystals left behind. EXAMPLE: Salt Water evaporating with salt crystals left behind.

21. Identification of Minerals What if you have two minerals that look exactly alike? What if you have two minerals that look exactly alike? How will you be able to tell one from the other? How will you be able to tell one from the other? STUDY THEIR CHARACTERISTICS STUDY THEIR CHARACTERISTICS Which is GOLD? Which is GOLD?

22. Identification of Minerals There are a number of different properties or characteristics that can give you clues to recognize different materials. There are a number of different properties or characteristics that can give you clues to recognize different materials. HARDNESS HARDNESS COLOR COLOR LUSTER LUSTER FRACTURE FRACTURE CLEAVAGE CLEAVAGE STREAK STREAK And Other Tests And Other Tests

23. Color Although color is an obvious feature of a mineral, it is often unreliable for identification. Although color is an obvious feature of a mineral, it is often unreliable for identification. Slight impurities can contaminate the mineral changing its color. Slight impurities can contaminate the mineral changing its color. Example: Quartz can be white, pink, or even purple. Example: Quartz can be white, pink, or even purple.

25. Luster Luster is the way a mineral reflects light. Luster is the way a mineral reflects light. It is often described as either metallic or nonmetallic. It is often described as either metallic or nonmetallic.

26. Streak If you were to scratch a mineral against a hard surface, like a porcelain tile it would leave behind a streak of colored powder. If you were to scratch a mineral against a hard surface, like a porcelain tile it would leave behind a streak of colored powder. Scientist use a streak plate to do the streak test. Scientist use a streak plate to do the streak test.

27. Streak While a mineral’s color may change, the color of its streak usually does not. Streak is often a much more helpful way to use color to identify a mineral. While a mineral’s color may change, the color of its streak usually does not. Streak is often a much more helpful way to use color to identify a mineral. Where do you use streak in your everyday life? Writing with a pencil on paper. Which mineral do you use to leave the streak? Graphite

28. Hardness The measure of how easily a mineral can be scratched is known as its hardness. The measure of how easily a mineral can be scratched is known as its hardness. Hardness of a mineral has nothing to do with whether it breaks easily or not. Hardness of a mineral has nothing to do with whether it breaks easily or not. Hardness is measured by using THE MOH’S HARDNESS SCALE, which is a scale that ranks ten common minerals hardness. Hardness is measured by using THE MOH’S HARDNESS SCALE, which is a scale that ranks ten common minerals hardness.

29. Hardness The Moh’s Hardness Scale is ranked from 1 – 10. The Moh’s Hardness Scale is ranked from 1 – 10. Talc is the softest mineral (1). Talc is the softest mineral (1). Diamond is the hardest mineral (10). Diamond is the hardest mineral (10).

30. Cleavage The way a mineral breaks apart is another way that is helpful in identifying it. The way a mineral breaks apart is another way that is helpful in identifying it. Sometimes when you break a mineral, it will break along flat smooth surfaces. Sometimes when you break a mineral, it will break along flat smooth surfaces. This results in a nice clean cut. This results in a nice clean cut.

31. Cleavage This is called cleavage. This is called cleavage. Think of the way a sharp meat cleaver cuts meat. Nice, clean cuts. Think of the way a sharp meat cleaver cuts meat. Nice, clean cuts.

32. Fracture Sometimes, minerals do not break in nice clean, flat cuts. Sometimes, minerals do not break in nice clean, flat cuts. Minerals that break along flat, smooth surfaces are said to fracture. Minerals that break along flat, smooth surfaces are said to fracture. The way a mineral break depends on the strength and arrangements of atomic bonds within the mineral. The way a mineral break depends on the strength and arrangements of atomic bonds within the mineral.

33. Cleavage and Fracture Minerals with Cleavage Minerals with Cleavage Mica Mica Calcite Calcite Halite Halite Fluorite Fluorite Minerals that Fracture Minerals that Fracture Quartz Quartz Olivine Olivine All minerals fracture to some extent…even those with cleavage do not break perfectly all the time. All minerals fracture to some extent…even those with cleavage do not break perfectly all the time.

34. Specific Gravity Minerals can be identified by comparing the weights of equal samples. Minerals can be identified by comparing the weights of equal samples. The specific gravity of a mineral is the ratio of its weight compared to the weight of an equal volume of water. The specific gravity of a mineral is the ratio of its weight compared to the weight of an equal volume of water. SG = WEIGHT OF MINERAL SG = WEIGHT OF MINERAL Weight in equal volume of water. Weight in equal volume of water.

35. Specific Gravity Gold has a specific gravity of 19 Gold has a specific gravity of 19 Pyrite has a specific gravity of 5 Pyrite has a specific gravity of 5 That means the gold is 19 times heavier than water and pyrite is 5 times heavier. If gold and pyrite look the same, you can tell them apart by finding their specific gravity. If you were to lift two different minerals, the one with the higher specific gravity would feel heavier.

36. Magnetism Magnetism: Some minerals are attracted to magnets and metals. Magnetism: Some minerals are attracted to magnets and metals.

37. Acid test Acid Test: Weak HCL acid on carbonate minerals (Those with CO 2 ) will produce a chemical reaction. Acid Test: Weak HCL acid on carbonate minerals (Those with CO 2 ) will produce a chemical reaction. CO 2 is given off as bubbles. CO 2 is given off as bubbles.

38. Smell Smell: Some minerals have a peculiar smell Smell: Some minerals have a peculiar smell Example: Sulfur Example: Sulfur

39. Taste Some Minerals have a peculiar taste. Example: Halite

40. Touch Some Minerals have a peculiar feel. Some Minerals have a peculiar feel. Example: Talc (Soapy) or Graphite (Silky) Example: Talc (Soapy) or Graphite (Silky)

41. Double Refraction Light enters the mineral as one beam of light. Light enters the mineral as one beam of light. Then it separates into 2 beams Then it separates into 2 beams You will see 2 objects You will see 2 objects Example: Calcite Example: Calcite

42. Fluorescence Some minerals glow brightly under a black light. Some minerals glow brightly under a black light. Minerals glow because they have impurities in them called activators Minerals glow because they have impurities in them called activators