Chapter 13 Section 1 What Is a Mineral? • A mineral is a naturally formed, inorganic solid that has a definite crystalline structure. How do we know if something is a mineral? • Does it have a crystalline structure? • Is it a nonliving material? • Is it a solid? • Is it formed in nature? Chapter 13 Section 1 What Is a Mineral? Elements are pure substances that cannot be separated or broken down into simpler substances by chemical means. 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. Crystal a solid whose atoms, ions, or molecules are arranged in a definite pattern Chapter 13 Section 1 What Is a Mineral? A mineral that is composed of only one element is a Native Element and two examples are Gold and Silver. Silicate minerals are minerals that contain a combination of silicon, oxygen, and one or more metals. Chapter 13 Section 1 What Is a Mineral? • 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 Sulfates Sulfides Oxides Chapter 13 Section 2 Identifying Minerals Identifying Minerals • Color - usually not the best way to identify a mineral. • luster - the way a mineral reflects light is called • Metallic • Submetallic • Nonmetallic Chapter 13 Section 2 Identifying Minerals • Streak - The color of a mineral in powdered form • Not always the same as minerals color • Use streak plate Chapter 13 Section 2 Identifying Minerals 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. Chapter 13 Section 2 Identifying Minerals • Hardness - a mineral’s resistance to being scratched is called Mohs hardness scale. Chapter 13 Section 2 Identifying Minerals • 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. Chapter 13 Section 2 Identifying Minerals Special Properties Chapter 13 Break Section 3 The Formation, Mining, and Use of Minerals Chapter 13 Section 3 The Formation, Mining, and Use of Minerals Formation of Minerals • Evaporating Salt Water When a body of salt water dries up, minerals such as gypsum and halite are left behind. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Metamorphic Rocks When changes in pressure, temperature, or chemical makeup alter a rock, metamorphism takes place. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Hot-Water Solutions Groundwater works its way downward and is heated by magma, and then reacts with minerals to form a hot liquid solution. • Dissolved metals and other elements crystallize out of the hot fluid to form new minerals, such as gold, copper, sulfur, pyrite, and galena. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Limestones Surface water and groundwater carry dissolved materials into lakes and seas, where they crystallized on the bottom. • Minerals that form in this environment include calcite and dolomite. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Pegmatites As magma rises upward from the Earth’s crust, it can form teardrop-shaped bodies called pegmatites. • Many gemstones such as topaz and tourmaline, form in pegmatites. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Plutons As magma rises upward through the crust, it sometimes stops moving before it reaches the surface and cools slowly, forming millions of mineral crystals. • Eventually, the entire magma body solidifies, forming minerals such as mica, feldspar, magnetite, and quartz. Chapter 13 Chapter 13 Section 3 The Formation, Mining, and Use of Minerals Mining • Ore - a mineral deposit large enough and pure enough to be mined for profit. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Surface Mining When mineral deposits are located at or near the surface of the Earth, surfacemining methods are used to remove the minerals. • Types of surface mines include open pits, surface coal mines, and quarries. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Subsurface Mining methods are used when mineral deposits are located too deep within the Earth to be surface mined. • Subsurface mining often requires that passageways be dug into the Earth to reach the ore. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals •Mining can destroy or disturb the habitats of plants and animals. • Waste products from a mine may get into water sources, which pollutes surface water and ground water. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Reclamation is the process by which land used for mining is returned to its original state. • Reducing our need for minerals by recycling is another way to reduce the effects of mining. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals The Use of Minerals • Metallic Minerals are good conductors of heat and electricity. They can be processed for various uses, including building aircraft, automobiles, and communications and electronic equipment. • Examples of useful metallic minerals include gold, silver, and copper. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Nonmetallic Minerals are good insulators of electricity. They have uses that range from glass-making to producing computer chips. • Calcite, one nonmetallic mineral, is a major component of concrete, which is used in building roads, buildings, bridges and other structures. Chapter 13 Section 3 The Formation, Mining, and Use of Minerals • Gemstones are highly valued for their beauty and rarity, than for their usefulness.