Still Learning About Rocks!!!!!

Chapter 2 Study Guide for Test on October 25th --- "Minerals and Rocks"

Study Guide – Chapter 2 Test—Minerals and Rocks

KNOW ALL OF YOUR VOCABULARY!!!  TAKE HOME YOUR VOCABULARY FOLDER!!!

THERE WILL BE A MATCHING OR SHORT ANSWER QUESTION FOR THESE WORDS!!!

Minerals—natural occurring solids that can form by inorganic (not living) processes and that have a crystal structure and a definite chemical composition!

For a substance to be a mineral, it must have all five of these characteristics:

1-naturally occurring

2-solid

3-crystal structure

4-forms by inorganic processes

5-definite chemical composition

QUARTZ is a mineral!

How are minerals identified?

Answer:  Each mineral has characteristic properties that can be used to identify it.  These properties are:

1-color

2-streak-the color of its powder

3-luster-how light is reflected from a mineral’s surface

Types of luster are:

-metallic

-silky

-waxy, greasy, earthy, or pearly

-glassy

4-hardness

THE HARDEST MINERAL IS A DIAMOND!

5-density—mass in a given space

6-crystal structure

8-cleavage and fracture

9-special properties—Examples:  Calcite bends light to produce double images!  Some minerals conduct electricity, glow when placed under ultraviolet light, or are magnetic.

How do minerals form?

1-organic materials

2-minerals from solutions

3-minerals from magma and lava

How do geologists classify rocks?

Answer:  To study a rock sample, geologists observe the rock’s mineral composition, color, and texture.

What are the three major groups of rocks?

1-igneous—forms from the cooling of magma or lava—Magma hardens underground to form rock.  The lava erupts, cools, and hardens to form rock on the Earth’s surface.

2-sedimentary--forms when small particles of rocks or the remains of plants and animals are pressed and cemented together—Forms in layers that are buried below the surface.

3-metamorphic—forms when a rock is changed by heat or pressure, or by chemical reaction.  Most metamorphic rocks form deep underground!

How do geologists classify igneous rocks?

Answer:  Igneous rocks are classified by their:

1-origin—Igneous rocks may form on (extrusive igneous rock) or beneath (intrusive igneous rock) the Earth’s surface!

BASALT IS THE MOST COMMON EXTRUSIVE ROCK!

GRANITE IS THE MOST ABUNDANT TYPE OF INTRUSIVE ROCK IN CONTINENTAL CRUST!

2-texture—the texture depends on the size and shape of its mineral crystals (except the different types of volcanic glass—igneous rocks that lack a crystal structure).

3-mineral composition—The silica content of magma and lava can vary.  Lava that is low in silica usually forms dark-colored rocks such as basalt!  Magma that is high in silica usually forms light-colored rocks such as granite!

How are igneous rocks used?

Answer:  Igneous rocks are used as tools and building materials.

How do sedimentary rocks form?

Answer:  Most sedimentary rocks are formed through a sequence of processed:

1-weathering

2-erosion

3-deposition

4-compaction

5-cementation

What are the three major types of sedimentary rocks?

1-clastic rocks-formed when rock fragments are squeezed together

2-organic rocks-formed where the remains of plants and animals are deposited in layers

3-chemical rocks-formed when minerals dissolved in a water solution crystallize

How are sedimentary rocks used?

Answer:  Sedimentary rocks have been used throughout history for tools and building.

What are metamorphic rocks?

Answer:  Any rock that forms from another rock as a result of changes in heat or pressure (or both heat and pressure) is a metamorphic rock.

How are metamorphic rocks classified?

Answer:  Geologists classify metamorphic rocks according to the arrangement of the grains making up the rocks.

Foliated rocks—describes the thin, flat layering found in most metamorphic rocks.

Examples of foliated rocks:  gneiss and slate

Nonfoliated rocks—the mineral grains in these rocks are arranged randomly.

Examples of nonfoliated rocks:  marble and quartzite

How are metamorphic rocks used?

Answer:  The metamorphic rocks marble and slate are important materials for building and sculpture.

What is the rock cycle?

Answer:  The rock cycle is a series of processes that occur on Earth’s surface and in the crust and mantle that slowly change rocks from one kind to another.

Example:  Weathering can break down granite into sediment that later forms sandstone!

The Beauty of Crystals

Students to Learn about the 3 Types of Rocks!!!!

In the next week or two, the students in our class will be making edible rocks!!!!!  This fun activity concretely demonstrates the steps that are necessary for the three different types of rocks (sedimentary, igneous, and metamorphic) to be formed.  PLUS, students get to eat their finished products! :)

https://www.youtube.com/watch?v=pg_jKJFbA2A

Geologist Devin Dennis will lead the way in the Geology Kitchen!