"The Most Common Mineral Group in Earth's Crust"

1. Warm Up 9/27 Warm Up 9/27 1) The most common mineral group in Earth’s crust is the ____________. 1) The most common mineral group in Earth’s crust is the ____________. a. Carbonates c. Oxides a. Carbonates c. Oxides b. Silicates d. Sulfides b. Silicates d. Sulfides 2) What are the building blocks of minerals? 2) What are the building blocks of minerals? a. Elements c. Rocks a. Elements c. Rocks b. Electrons d. Isotopes b. Electrons d. Isotopes 3) The building block of the silicate minerals is called the _______________. 3) The building block of the silicate minerals is called the _______________. a. Silicon-aluminum triangle a. Silicon-aluminum triangle b. Aluminum-oxygen tetrahedron b. Aluminum-oxygen tetrahedron c. Silicon-oxygen tetrahedron c. Silicon-oxygen tetrahedron d. Silicon-oxygen triangle d. Silicon-oxygen triangle Answers: 1) b. 2) a. 3) c. Answers: 1) b. 2) a. 3) c.

2. Properties of Minerals Properties of Minerals Chapter 2, Section 3 Chapter 2, Section 3

3. Color Color  Small amounts of different elements give the same mineral different colors  Small amounts of different elements give the same mineral different colors  This property is not often used to identify minerals  This property is not often used to identify minerals

4. Streak Streak  Streak is the color of a mineral in its powdered form  Streak is the color of a mineral in its powdered form  Streak is obtained by rubbing a mineral across a streak plate  Streak is obtained by rubbing a mineral across a streak plate  The streak’s color never varies between different colors of a mineral  The streak’s color never varies between different colors of a mineral  Can also see the differences between minerals with metallic lusters and minerals with nonmetallic (no streak is produced)  Can also see the differences between minerals with metallic lusters and minerals with nonmetallic (no streak is produced)

5. Luster Luster  Luster is used to describe how light is reflected from the surface of a mineral  Luster is used to describe how light is reflected from the surface of a mineral  Minerals that have the appearance of metals have metallic lusters  Minerals that have the appearance of metals have metallic lusters  Minerals with a nonmetallic luster are described with many different adjectives (glassy, pearly, silky, earthy, brilliant)  Minerals with a nonmetallic luster are described with many different adjectives (glassy, pearly, silky, earthy, brilliant)

6. Luster Luster

7. Crystal Form Crystal Form  Crystal form is the visible expression of a mineral’s internal arrangement of atoms  Crystal form is the visible expression of a mineral’s internal arrangement of atoms  When a mineral develops slowly, it will form a well-defined crystal  When a mineral develops slowly, it will form a well-defined crystal  Most of the time, minerals are competing for space, resulting in an intergrown crystal structure  Most of the time, minerals are competing for space, resulting in an intergrown crystal structure

8. Crystal Form Crystal Form

9. Concept Check Concept Check  What two conditions produce crystals with well-defined faces?  What two conditions produce crystals with well-defined faces?  Unrestricted space and a slow rate of formation  Unrestricted space and a slow rate of formation

10. Hardness Hardness  Hardness – a measure of the resistance of a mineral to being scratched  Hardness – a measure of the resistance of a mineral to being scratched  The Mohs scale consists of 10 minerals arranged from 10 (hardest) to 1 (softest)  The Mohs scale consists of 10 minerals arranged from 10 (hardest) to 1 (softest)  Diamond, the hardest mineral on Earth, can scratch anything  Diamond, the hardest mineral on Earth, can scratch anything  You can use your fingernail, copper plate, glass, quartz, etc.  You can use your fingernail, copper plate, glass, quartz, etc.

12. Concept Check Concept Check  What are three of the most useful properties for identifying unknown minerals?  What are three of the most useful properties for identifying unknown minerals?  Hardness, streak, and luster  Hardness, streak, and luster

13. Cleavage Cleavage  Cleavage is the tendency of a mineral to cleave, or break, along flat, even surfaces  Cleavage is the tendency of a mineral to cleave, or break, along flat, even surfaces  Some minerals have structures which allow them to break easily into sheets (mica)  Some minerals have structures which allow them to break easily into sheets (mica)  Other minerals have very strong bonds, and fracture instead  Other minerals have very strong bonds, and fracture instead

14. Cleavage Cleavage

15. Fracture Fracture  Minerals that do not show cleavage when broken are said to fracture (the uneven breakage of a mineral)  Minerals that do not show cleavage when broken are said to fracture (the uneven breakage of a mineral)

16. Concept Check Concept Check  How are cleavage and fracture different?  How are cleavage and fracture different?  Cleavage is the tendency for a mineral to break along flat, even surfaces. Fracture is the uneven breakage of a mineral.  Cleavage is the tendency for a mineral to break along flat, even surfaces. Fracture is the uneven breakage of a mineral.

17. Density Density  Density is the property of all matter that is the ratio of an object’s mass to its volume  Density is the property of all matter that is the ratio of an object’s mass to its volume Density (d) = mass (m) / Volume (V) Density (d) = mass (m) / Volume (V)  Density is usually expressed in g/cm 3 in Geology  Density is usually expressed in g/cm 3 in Geology  Many common minerals have densities between 2 and 5 g/cm 3  Many common minerals have densities between 2 and 5 g/cm 3  The density of a pure mineral is a constant value, and can be used to determine the purity or identity of some minerals  The density of a pure mineral is a constant value, and can be used to determine the purity or identity of some minerals

18. Distinctive Properties of Minerals Distinctive Properties of Minerals  Some minerals can be recognized by other distinctive properties  Some minerals can be recognized by other distinctive properties  Some minerals are magnetic, some you can see through, some streaks smell like rotten eggs, and some will bubble when acid is placed on them  Some minerals are magnetic, some you can see through, some streaks smell like rotten eggs, and some will bubble when acid is placed on them  A mineral’s properties depend on the elements that compose the mineral (its composition) and its structure (how its atoms are arranged)  A mineral’s properties depend on the elements that compose the mineral (its composition) and its structure (how its atoms are arranged)

19. Assignment Assignment  Read Chapter 2, Section 3 (pg. 50-55)  Read Chapter 2, Section 3 (pg. 50-55)  Do Section 2.3 Assessment #1-6 (pg. 55)  Do Section 2.3 Assessment #1-6 (pg. 55)  Study for the Chapter 2 Quiz!  Study for the Chapter 2 Quiz!