INSIDE EARTH Projected Test: January 22
Chapter Four Minerals Study Guide
Section One BIG IDEAS Properties of Minerals
- A mineral is a naturally occurring, inorganic solid that has a definite chemical composition and crystal shape.
- Each mineral can be identified by its own physical and chemical properties.
- Some of the properties of a mineral include hardness, color, streak, luster, density, cleavage, and fracture, and crystal structure
- Hardness is measured by the Moh’s hardness scale
- Minerals usually consist of two or more elements joined together in a compound
VOCABULARY
Mineral – a naturally-occurring, inorganic solid that has a crystal structure and a definite chemical compound
Crystal – a solid in which the atoms are arranged in a pattern that repeats again and again
Element – a substance composed of a single kind of atom
Compound– a substance in which two or more elements are chemically joined
Luster – the way material reflects light
Moh’s Hardness Scale– a scale ranking ten minerals from softest (1-talc) to hardest (10- diamond)
Fluorescence – the property of a mineral in which a mineral glows under an ultraviolet light
Streak – the color of a mineral’s powder
Cleavage- a mineral’s ability to split easily along flat surfaces
Fracture- the way a mineral looks when it breaks apart in an irregular way
Inorganic – not formed from the remains of living things
Gemstone– a hard, colorful mineral that has a brilliant and glassy luster
Section Two BIG IDEAS How Minerals Form
- Minerals form inside Earth through crystallization as magma and lava cools.
- Minerals form on Earth’s surface when materials dissolved in water crystallize through evaporation
3. Mineral deposits on the ocean floor form from solutions heated by magma.
Section Three BIG IDEAS Mineral resources
1. Minerals are useful as the source of metals(elements with shiny, hard surfaces and can conduct electricity and heat), colorful gemstones(valued for durability and brilliant luster), and many other materials.
2. Ores (contain metal or an economically useful mineral) can be removed from the ground and smelted (heated) to extract a valuable metal, such as iron.
3. Alloys, solid mixtures of two or more metals, can create special metals such as stainless steel.
INSIDE EARTH
Chapter Five Rocks Study Guide
Section One BIG IDEAS Classifying Rocks
1. A rock is a hard piece of Earth’s crust (hard surface)
2. Geologists classify rocks according to their color, texture, mineral composition, and origin.
3. The three kinds of rocks are igneous, metamorphic, and sedimentary.
VOCABULARY
texture – the look and feel of a rock’s surface
grain– a particle of mineral or other rock that gives a rock its texture
igneous rock – a type of rock that forms from the cooling of molten rock at or below the Earth’s surface
metamorphic rock– a type of rock that forms from an existing rock that is changed by
heat, pressure, or chemical reactions
sedimentary rock– a type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together
Section Two BIG IDEAS Igneous Rock
- Igneous Rocks form from magma and lava
- Igneous rocks are classified according to their origin, texture, and composition.
- Igneous rocks origin can be identified as extrusive (formed outside the Earth’s surface) or intrusive (formed inside the Earth’s crust).
- An example of an extrusive rock is basalt formed from the lava that flows out onto the bottom of the ocean floor. An example of an intrusive rock is granite formed from magma in the Earth’s crust.
- Igneous rocks that cooled slowly are coarse-grained while those which cool quickly tend to be fine grained.
Section Three BIG IDEAS Sedimentary Rocks
- Most sedimentary rocks form from sediments that are compacted and cemented together.
- The three types of sedimentary rocks are clastic, organic, and chemical
VOCABULARY
Clastic rock- a sedimentary rock that forms when rock fragments are squeezed together under high pressure
Organic rock – sedimentary rock that forms where the remains of organisms are deposited in thick layers
Chemical rock – sedimentary rock that forms when minerals crystallize from a solution
Compaction – the process by which sediments are pressed together under their own weight. An example of a rock formed this way is shale.
Cementation – the process by which dissolved minerals crystallize and glue particles of sediment together into one mass. One example of a rock formed this way is coquina.
Section Four BIG IDEAS Metamorphic Rocks
- In a process that takes place deep beneath the surface, tremendous heat and pressure can change any type of rock into metamorphic rock
- Geologists classify metamorphic rock according to whether the rock is foliated or nonfoliated.
VOCABULARY
Foliated- term used to describe metamorphic rocks whose grains are arranged in parallel layers or bands. Foliated rocks tend to break into layers.
Nonfoliated – term used to describe lack of banding
Section Five BIG IDEAS The Rock Cycle
- The series of processes on and beneath the Earth’s surface that change rocks from one type of rock to another is called the rock cycle
Important: You will be expected to interpret and label a diagram depicting the rock cycle. Be sure that you understand this cycle and how rocks move through it.