ES 9A.STUDENTS KNOW THE RESOURCES OF MAJOR ECONOMIC IMPORTANCE IN CALIFORNIA AND THEIR RELATION TO CALIFORNIA’S GEOLOGY. Ch 5. Minerals

Characteristics of Minerals To be a mineral, a substance must have four characteristics:  must be inorganic—it cannot be made of or by living things;  must occur naturally—it cannot be man-made;  must be a crystalline solid;  must have a consistent chemical composition.

Kinds of Minerals All minerals can be classified into two main groups — based on their chemical compositions. silicate mineral contains a combination of silicon and oxygen, may also contain one or more metals Silicate minerals make up 96% of Earth’s crust.

nonsilicate mineral does not contain compounds of silicon and oxygen  Make up about 4% of Earth’s crust.

Physical Properties of Minerals Color is unreliable for the identification of minerals. can be affected by impurities or by weathering processes. Streak the color of a mineral in powdered form determined by rubbing some of the mineral against an unglazed ceramic tile called a streak plate.

Luster the way in which a mineral reflects light metallic luster if it reflects light All other minerals have nonmetallic luster.  Ex. glassy, waxy, pearly, brilliant, and earthy.

Cleavage the tendency of a mineral to split along specific planes of weakness to form smooth, flat surfaces Fracture the manner in which a mineral breaks along either curved or irregular surfaces

Physical Properties of Minerals Hardness the ability of a mineral to resist scratching is called hardness. Mohs hardness scale the standard scale against which the hardness of minerals is rated. The strength of the bonds between the atoms that make up a mineral’s structure determines the hardness of a mineral.

STUDENTS KNOW HOW TO EXPLAIN THE PROPERTIES OF ROCKS BASED ON THE PHYSICAL AND CHEMICAL CONDITIONS IN WHICH THEY FORMED, INCLUDING PLATE TECTONIC PROCESSES Ch 6 ROCKS

Three Major Types of Rock Rock: The material that makes up the solid parts of Earth. Rocks are classified based on the processes that form.

3 Types of Rocks 1. Igneous rock forms when magma, or molten rock, cools and hardens. 2.Sedimentary rock forms when sediment deposits that form when rocks, mineral crystals, and organic matter have been broken into fragments are compressed or cemented together. 3.Metamorphic rock forms when existing rock is altered by changes in temperature, pressure, or by chemical processes.

Chapter 6 The Rock Cycle Geologic forces and processes cause rock to change from one type to another. rock cycle the series of processes in which rock forms, changes from one form to another, is destroyed, and forms again by geological processes

Chapter 6 The Formation of Magma igneous rock rock that forms when magma cools and solidifies The three factors that affect whether rock melts include 1) temperature, 2) pressure, 3) the presence of fluids in the rock.

Chapter 6 The Formation of Magma, continued Partial Melting Different minerals have different melting points As the temperature increases and as other minerals melt, the magma’s composition changes.

Chapter 6 The Formation of Magma, continued Fractional Crystallization The crystallization and removal of different minerals from the cooling magma. Minerals that have the highest freezing points crystallize first.

Chapter 6 Textures of Igneous Rocks intrusive igneous rock rock formed beneath Earth’s surface extrusive igneous rock rock formed at Earth’s surface

Chapter 6 Textures of Igneous Rocks, continued Coarse-Grained Igneous Rock Because intrusive igneous rocks cool slowly, they commonly have large mineral crystals. Fine-Grained Igneous Rock Because extrusive igneous rocks cool rapidly, they are commonly composed of small mineral grains.

Sedimentary Rock 1. Rocks, mineral crystals, and organic matter that have been broken into fragments. 2. Sediment is carried away and deposited by water, ice, and wind. 3. Sediment deposits are compressed or cemented together and harden they form sedimentary rock.

Section 3 Sedimentary Rock Chapter 6 Chemical Sedimentary Rock chemical sedimentary rock sedimentary rock that forms when minerals precipitate from a solution or settle from a suspension

Section 3 Sedimentary Rock Chapter 6 Organic Sedimentary Rocks organic sedimentary rock sedimentary rock that forms from the remains of plants or animals

Section 3 Sedimentary Rock Chapter 6 Organic Sedimentary Rocks, continued The diagram below shows the formation of organic limestone.

Section 3 Sedimentary Rock Chapter 6 Clastic Sedimentary Rock clastic sedimentary rock sedimentary rock that forms when fragments of preexisting rocks are compacted or cemented together

Chapter 6 Formation of Metamorphic Rocks One type of rock changes into metamorphic rock because of chemical processes or changes in temperature and pressure Heat, pressure, and hot fluids cause some minerals to change into other minerals.

Chapter 6 Formation of Metamorphic Rocks, continued Contact Metamorphism A change in the texture, structure, or chemical composition of a rock due to contact with magma Regional Metamorphism A change in the texture, structure, or chemical composition of a rock due to changes in temperature and pressure over a large area, generally are a result of tectonic forces

Chapter 6 Classification of Metamorphic Rocks Foliated Rocks Minerals grains are arranged in planes or bands Extreme pressure may cause the mineral crystals in the rock to realign or regrow to form parallel bands.

Chapter 6 Classification of Metamorphic Rocks, continued Nonfoliated Rocks Minerals grains are not arranged in planes or bands