1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Minerals of the Earth’s Crust Section 1 What Is a Mineral? Section 2 Identifying Minerals Section 3 The Formation, Mining, and Use of Minerals Chapter 3 Table of Contents

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Bellringer Compare the pencil lead and the diamond in the photographs below. Both substances are composed of carbon. How can the same element form two substances with such different properties? Chapter 3

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Chapter 3 Describe the structure of minerals. Describe the two major groups of minerals. Objectives

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Chapter 3 Mineral Structure A mineral is a naturally formed, inorganic solid that has a definite crystalline structure. You can tell whether an object is a mineral by asking four questions. Crystalline Structure of Diamond Crystalline Structure of Lead

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Chapter 3 Mineral Structure, continued Is it a nonliving material? Is it a solid? Does it have a crystalline structure? Is it formed in nature?

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Chapter 3 Mineral Structure, continued To understand crystalline structure, you need to know a little about the elements that make up a mineral. Elements = pure substances that cannot be separated or broken down into simpler substances by chemical means.

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Write down whether the following items are Elements or Compound? WaterNitrogen CarbonCarbon Dioxide GoldOxygen SaltGlucose Bellringer

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Chapter 3 Mineral Structure, continued Atoms and Compounds Minerals may be either elements or compounds. A compound is a substance made of atoms of two or more different elements joined by chemical bonds. Compound Element

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Chapter 3 Mineral Structure, continued A mineral that is composed of only one element is called a native element. Gold and silver are examples of native elements. Native Gold Native Silver Native Diamond Native Graphite

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu BellringerHow many can you name?

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Chapter 3 Mineral Structure, continued Solid, geometric forms of minerals produced by a repeating pattern of atoms that is present through- out the mineral are called crystals. A crystal’s shape is determined by the arrangement of the atoms within the crystal. The arrangement of atoms is determined by the kinds of atoms that make up the mineral.

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Chapter 3 Two Groups of Minerals Minerals are divided into two groups based on their chemical composition. Silicate minerals are minerals that contain a combination of silicon, oxygen, and one or more metals. (Diagram of compound on next slide SiO 2 ) Examples of silicate minerals are quartz, feldspar, and mica. (See following slides)

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Silicon

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Quartz Mica

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Mineral? Chapter 3 Two Groups of Minerals, continued Nonsilicate minerals are minerals that do not contain compounds of silicon and oxygen. There are six main classes of nonsilicate minerals. Native Elements Carbonates Halides (Group1 + Group17) Oxides (O plus other element) Sulfates Sulfides (contain sulfur) These are stinky

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Bellringer Look at the mineral samples provided by your teacher. List as many phrases as you can to describe each sample. Chapter 3

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3 Identify seven ways to determine the identity of minerals. Explain special properties of minerals. Objectives

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3 Identifying Minerals You can determine the identity of a mineral by noting different properties. Color Minerals display a wide variety of colors, and often the same mineral can be found in many different colors. Because of this, color is usually not the best way to identify a mineral.

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3 Identifying Minerals, continued The way a mineral reflects light is called luster. There are three types of mineral luster: Metallic Submetallic Nonmetallic

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3 Identifying Minerals, continued The color of a mineral in powdered form is called the mineral’s streak. A mineral’s streak can be found by running the mineral against a piece of unglazed porcelain called a streak plate. The color of a mineral’s streak is not always the same as the color of the mineral sample.

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3 Cleavage and Fracture Different types of minerals break in different ways. Cleavage is the tendency of some minerals to break along smooth, flat surfaces. Fracture is the tendency of some minerals to break unevenly along curved or irregular surfaces.

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3 Hardness A mineral’s resistance to being scratched is called hardness. To determine the hardness of minerals, scientists use Mohs hardness scale, shown on the next slide.

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3 Density Density is the measure of how much matter is in a given amount of space. Density is a ratio of an object’s mass to its volume. Different minerals have different densities.

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3 Special Properties Some properties are particular to only a few types of minerals. The properties shown on the next slide can help you quickly identify some minerals.

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Identifying Minerals Chapter 3