Unit 3 Lesson 2 What Are Minerals? Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 What Are Minerals? Florida Benchmark SC.4.E.6.2 Identify the physical properties of common earth-forming minerals, including hardness, color, luster, cleavage, and streak color, and recognize the role of minerals in the formation of rocks. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 What Are Minerals? A mineral is any nonliving solid that has a crystal form. All minerals form in nature. There are more than 4,700 different kinds of minerals. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 What Are Minerals? Minerals are made up of particles that form a shape that is repeated. The repeating shape of the particles forms the mineral crystal. A mineral is always made up of the same elements. Copyright © Houghton Mifflin Harcourt Publishing Company 4

Unit 3 Lesson 2 What Are Minerals? Which Mineral Is Which? Hardness is one property used to identify minerals. Hardness is the ability of one mineral to scratch another mineral. The Mohs scale is used to describe the hardness of a mineral. The softest minerals score 1 and the hardest minerals score 10. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 What Are Minerals? Which Mineral Is Which? Luster is another property used to identify minerals. It describes how minerals reflect light. The minerals copper, gold, and silver have a metallic luster. Talc and gypsum have an earthy luster. Some minerals have a glassy luster. Copyright © Houghton Mifflin Harcourt Publishing Company

Unique Properties of Minerals Unit 3 Lesson 2 What Are Minerals? Unique Properties of Minerals The way a mineral breaks also is used to identify it. If a mineral breaks with smooth, straight sides, it has cleavage. Minerals that do not break with smooth, straight sides fracture. Copyright © Houghton Mifflin Harcourt Publishing Company

Unique Properties of Minerals Unit 3 Lesson 2 What Are Minerals? Unique Properties of Minerals The color of a mineral’s streak also is used to identify it. Streak is the color of a mineral when it is rubbed against a white tile. The same type of mineral may come in different colors, but its streak is always the same color. Copyright © Houghton Mifflin Harcourt Publishing Company

Unique Properties of Minerals Unit 3 Lesson 2 What Are Minerals? Unique Properties of Minerals Some minerals have unusual properties that can be used to identify them. Calcite and fluorite glow under a black light. Calcite fizzes when you drop vinegar on it. Quartz conducts electricity. Copyright © Houghton Mifflin Harcourt Publishing Company