Book 2: Minerals and Rocks
Chapter 1: Properties of Minerals
Vocabulary Building
Mineral
Elements
Streak
Luster
Hardness
Mohs scale of hardness
Cleavage
Fracture
Fluorescence
Reactivity
Magnetism
Jack was an avid rock collector. Jack’s family has taken a summer vacation in the
Bahamas. While walking on the beach, Jack spotted a few rocks. He picked up three rocks.
One has a grainy feel to it, a second had large dark crystals, and a third had a wavy dark band
running through it. Jack put the rocks into his pocket, to examine later.
“Dad, I found these interesting rocks while we were on the beach this morning,” said
Jack. “Let’s have a look,” replied his dad. Jack showed his dad the rocks. “Well, Jack, you
have three different types of rocks here,” dad explained. “These rocks have properties that
make them unique. Do you know what make makes up rocks?” asked dad.
“No, dad, what are rocks made of?” Jack asked. “Rocks are made up of different types of
minerals. Minerals have properties that make them different from rocks. Jack wanted to find out
more about minerals and their properties. Jack went to his room to get his tablet. He began to
Google minerals.
.
Jack discovered that a mineral is a naturally occurring substance, that is, it is not
manmade. A mineral is inorganic, that means that it is not from substances that were once
part of a living thing. A mineral is always a solid. It is not a liquid or a gas. A mineral will have
a crystal structure, that is, it will line up in a repeated pattern. A mineral has a definite
chemical composition. It will always contain certain elements in definite proportions. These
five properties of a mineral is the mineral’s definition. “How can I remember the definition for a
mineral?” Jack asked himself. Back in third grade Jack remembered how his teacher taught hi,
to visualize pictures and make associations that could help him with word definitions and
meaning. Jack thought it would be neat to use an acronym to help him with this. “I got it! I will
use the acronym, N C I S ‘D,” exclaimed Jack excitedly.
As Jack researched further, he discovered that there were certain physical properties
that geologists use to identify individual minerals. These physical properties are actual tests that
can be performed on each mineral for its identification. There are about 4,000 known minerals.
Many look very similar, which makes it difficult to tell them apart! There are seven physical
properties and four special properties that we will be focus on in this chapter.
Jack went to his father’s study and took down one of his boxes of minerals. Looking at
the minerals, Jack looked at the minerals and noticed that a few had similar colors, some were
shiny, and the others looked dull and glassy. “How can you tell one mineral from the next?”
Jack said to himself. Jack resumed his research. The first physical property test is color.
Color is the least reliable and provides the least information about the identity of a mineral.
Most mineral have the same color, therefore color will provide the least information and is the
least reliable. Streak is the color minerals powder when rubbed against a piece of unglazed
porcelain tile. The steak may be the same color of the mineral, a different color, white, or clear
/colorless.
Luster describes how light is reflected from a mineral’s surface.
Minerals Density is described as mass per unit volume. The more mass a mineral has,
the greater its density. No matter what the size of the mineral is, big or tiny, the density will
always be the same.
Hardness is one of the best methods to test for the identity of a mineral is to test for its
hardness. The Mohs Scale of Hardness is a scale used to measure the hardness of a mineral.
It ranks minerals from 1 to 10 or from softest to hardest. Talc is softest at 1, apatite has a
hardness of 5, and diamond is hardest at 10. The hardness is determined by a scratch test
using your finger nail, a copper coin, knife, glass, or steal file.
Crystal structure is the repeated pattern or growth of the mineral’s atoms. The crystal
structure is based on the number and angle of the crystal faces. The crystal structure maybe
described as cubic, hexagonal, tetragonal, orthorhombic, monoclinic, or triclinic.
A mineral has cleavage if it breaks apart evenly and smoothly along a flat surface. A
mineral has fracture if it breaks apart unevenly or irregularly, so that it has jagged or pointed
edges.
Muscovite
CLEAVAGE
Cleavage in
one
direction.
Calcite
CLEAVAGE
Cleavage in
three
directions not
at right angles
(120o and
60o).
Rhombohedral
cleavage.
Quartz
FRACTURE
Mineral
does not
exhibit
cleavage;
it breaks
or
fractures
in an
irregular
manner.
Jack decided to sort his samples according to fracture and cleavage. He realized that
some of his samples didn’t fit into any of these categories, and some fit into more than one
category. Jack realized that some of his samples had special properties. Some minerals had
the special property of fluorescence, the mineral gloves under ultraviolet light. A mineral has
optical properties if it has the ability to bend light to produce a double image. A mineral has
reactivity if it will frizzle when place in vinegar or a weak acid. A mineral will have magnetism
if it attracts paper clips, iron staples, or iron filing. This mineral may contain iron.
Fluorescence
Optical properties
Reactivity
Magnetism
Jack summarizes his findings. The definition of a mineral is the characteristic of a
mineral. A mineral is naturally occurring, inorganic, solid with a chemical structure and a
definite chemical composition, or N C I S’ D. The physical properties are tests that maybe
performed on a mineral to identify a mineral. These physical properties are color, streak, luster,
hardness, cleavage, fracture, density, crystal structure. Special properties include fluorescence,
optical properties, reactivity, and magnetism.
Discussion questions:
1. Write your own definition of a mineral. Write your own acronym for the definition or
characteristic of a mineral.
2. What does it mean to say a mineral is “inorganic” or “naturally occurring”?
3. Name the seven physical properties that can be used to identify a mineral. Name the
four special properties that a mineral can have.
4. What is the difference between cleavage and fracture?
Extension: (Analysis/application)
1. Amber is a precious material used to make jewelry. It forms when the resin of pine trees
hardens into stone. Is Amber a mineral? Explain your reasoning.
Book 2: Minerals and Rocks
Chapter 2: Classifying Rocks
Vocabulary Building
Mineral composition
How many and how much of a mineral or minerals that a
rock contains.
Texture
The look and feel of a rock.
Rock forming minerals
10-15 different minerals that compose about 90% of all the
rocks in Earth's crust.
Coarse grained
Slowly cooling magma that makes an igneous rock with
large crystals.
Fine grained
Texture of an extrusive igneous rock as it cools quickly on
the surface of the Earth.
Igneous
A type of rock that forms from the cooling of molten rock at
or below the surface.
Sedimentary
A type of rock that forms when particles from other rocks or
the remains of plants and animals are pressed and
cemented together.
Metamorphic
A type of rock that forms from an existing rock that is
changed by heat, pressure, or chemical reactions.
Lithification
The process that converts sediments into solid rock by
compaction or cementation.
Jack focused his attention to the three rocks that he had collected on the beach. He
pulled them from his sample kit located on the shelf in his bedroom. One of the rocks had large
dark crystals, a second rock had a grainy feel to it, and a third had a wavy dark band running
through it. Jack wanted to find out more about how these rocks were classified. Jack went to
find his dad. “Dad, how do geologists identify different types of rocks?” asked Jack. “Rocks are
identified by their mineral composition, color, and texture. Since rocks are made up of a
mixture of minerals and other substances, these minerals are known as rock forming
minerals. There are about twenty minerals that are rock forming minerals. Once we know the
mineral composition of the rock, we’ll be able to identify the rock,” answered dad. “How does
color help in a rock’s identification?” asked Jack. Jack went to his tablet to research more.
Color provides information to the mineral’s composition. A rock that is light in color will
have high silica content. For example, granite is light in color with high silica content. Rocks
that are dark in color, like basalt, are low in silica. In addition to color, geologists look at the
grains or particles of minerals that make up the rock. Grains will describe a rock’s texture. The
rock’s texture is the look and feel of the rock’s surface.
In describing a rock’s texture, geologists examine the grain size, grain shape, and
grain pattern. When looking at grain size, geologists look to see if the grains are large and
easy to see. If the grains are large and easy to see, then these types of rocks are called
coarse-grained. If the grains are small and difficult to see, the rocks are called fine-grained.
Some rocks have grains that are not visible even under a microscope. This type of rock is
called no visible grain. Grain shape may include shapes of the mineral crystals or rock
fragments. These fragments maybe smooth, rounded, or jagged. Grains in a rock often form a
pattern. The pattern may be flat layers, swirling, or the grains may be randomly scattered in the
rock.
Courses grain
Gabbro
Fine Grain
Basalt
Scoria
No visible grain
Obsidian
Jack needed to find out how rocks are classified. He read that the classification is based
on the origin of the rock or where the rock was formed. Jack went in search of his dad. “Dad,
can you tell me how rocks are classified?” enquired Jack. “Rocks are classified into three major
categories. The classification is based on the origin of the rock itself,” continued dad. “These
classifications are igneous, sedimentary, and metamorphic rocks,” explained dad. Jack went
to his tablet to find out as much as he could about each classification of rock.
Jack read that igneous rocks are rocks that are formed from the cooling of lava or
magma. Sedimentary rocks are formed when particles of other rocks or the remains of plant
and/or animals are pressed and cemented together by lithification. These rocks are formed in
layers that are buried below the water surface. Metamorphic rocks are formed from any of the
three types of rocks that are changed by heat, pressure, or a chemical change in the crystal or
grain arrangement. Metamorphic rocks are formed deep underground.
Jack summarized his findings. Rocks are classified according to its mineral composition,
color, and texture. Texture is the look and feel of the rock. Texture is described by the grain
size, grain shape, and grain pattern. Grain is the particles of minerals that make up the rock.
Geologists place rocks into three categories according to their origin. Igneous rocks form the
cooling of lava or magma. Sedimentary rocks are formed by compaction and cementation of
other rock fragments underwater. Sedimentary rocks are formed in layers. Metamorphic rocks
are formed from heat, pressure, and chemical changes deep underground.
Discussion questions:
1.
Write about the three characteristics that geologists use to identify rocks.
2. Explain what text is and what factors geologists look at when describing the texture of
rocks.
3. Name the three types of rocks. Compare and contrast each type.
4. Research Conglomerate and Breccia, using Google. In your own words, compare the
grain size, grain shape, and grain pattern in each of these two types of rocks. Draw an
illustration of each.
Extension: (Analysis/application)
1. Gneiss is a group is a kind of rock that forms when heat and pressure inside Earth
change granite. To what group of classification of rocks does gneiss belong? Provide
evidence to support your answer.
Book 2: Minerals and Rocks
Chapter 3: Igneous Rocks
Vocabulary Building
Extrusive
Igneous rock that forms from lava on Earth's surface.
Basalt
A dark, dense, igneous rock with a fine texture, found in oceanic
crust.
Intrusive
A type of igneous rock that generally contains large crystals and
forms when magma cools slowly beneath Earth's surface.
Granite
A usually light-colored igneous rock that is found in continental
crust.
Texture
The look and feel of a rock.
Grain size
The size of the particles of minerals or other rocks that give a rock
its texture.
Grain shape
The shape of the particles of minerals or other rocks that give a
rock its texture.
Coarse grain
Slowly cooling magma that makes an igneous rock with large
crystals.
Fine grain
Extrusive igneous rock cools rapidly on the earth's surface, these
rocks have small crystals called fine grained. an example is
basalt.
No visible grain
No grains, or grains too small to see even with a microscope.
Rock is smooth and shiny.
“What do I already know about igneous rocks,” Jack thought to himself. “I know
that igneous rocks are formed from magma or lava. “Well, exactly how do geologists
classify different types of igneous rocks?” Jack wondered. Jack went in search of his
tablet to Google the information.
According to his research, igneous rocks are classified according to its place of
origin, texture, and mineral content. Origin means where the rock is formed. If the rock
is formed when lava from a volcano reaches the surface of Earth, the rock is classified
as extrusive rock. (“ex” means outside of). Basalt is the most common type of
extrusive igneous rock that covers the Earth’s ocean floors. Igneous rock formed when
magma slowly cools beneath the Earth’s surface is called intrusive rock. The most
common type of intrusive igneous rock is granite. Granite forms the core of the
mountain ranges.
Jack continued his research about texture. Texture is the look and feel of a rock.
Texture depends on the size and shape of the grains of the minerals that make up the
rocks. Intrusive and extrusive rocks have different textures. Intrusive rocks have large
crystal and the crystal can be easily seen. They are described as course grained.
Extrusive rocks are fine grained or no visible grain, because the lava cooled so rapidly
that the crystal has little or no time to grow. So in some extrusive rocks the crystals are
extremely tiny, or have a glassy texture. Jack wanted to find examples of course
grained, fine grained, and no visible grain rock.
Rhyolite
Obsidian
Pegmatite
Porphyry
Jack recalls that most minerals contain silica. Silica is a material made from oxygen and silicon
dioxide. Silica is a light colored material. If a rock has high silica content, the rock will be light in
color. If the rock has low silica content, the rock will be dark in color. A rock’s mineral
composition will determine its color.
Granite
“What are some of the uses of igneous rocks?” Jack wondered. He remembered his
mom looking through catalogs and rock samples in search of countertops. “What makes
igneous rocks useful?” continued Jack. Jack went in search of his dad. “Well Jack, igneous
rocks are hard, dense, and durable. These properties make igneous rocks excellent building
materials. Igneous rocks are used to make cobble stones, curbstones, kitchen countertops, and
floors. Pumice is used as an abrasive to polish surfaces.
Jack summarizes his findings. Igneous rock can be classified according to their place of
origin. If the lava cools rapidly on the surface of Earth, the rock is called an extrusive igneous.
The lava cooled so rapidly on reaching the surface, the crystals didn’t have time to grow. If the
cooling was instantaneous, the rocky will have a glassy texture. Extrusive igneous rocks are
described as fine grained or no visible grain. If the magma inside the volcano cooled slowly, the
mineral crystal will have lots of time to grow. These rocks are called intrusive igneous rocks.
They are described as course grained, because the crystals are large and easy to see.
Discussion questions
1. How are igneous rocks classified?
2. Differentiate between intrusive and extrusive igneous rocks.
3. What characteristics make igneous rocks useful as building material? Give examples of
the uses of igneous rocks.
Resource
Geology.com
Book 2: Minerals and Rocks
Chapter 4: Sedimentary Rocks
Vocabulary Building
Sediments
Loose materials such as rock fragments, mineral grains, and bits of shell
that have been moved by wind, water, ice, or gravity.
Sedimentary rocks
A type of rock that forms when particles from other rocks or the remains
of plants and animals are pressed and cemented together.
Weathering
Chemical or physical process that breaks down rocks into smaller pieces.
Erosion
Process by which weathered rock and soil are moved from one place to
another.
Deposition
Process in which sediment is laid down in new locations
Compaction
The processes by which sediments are pressed together under their own
weight.
Cementation
Cementation is the process in which dissolved minerals crystallize and
glue particles of sediment together.
Clastic rocks
Sedimentary rock that forms when fragments of preexisting rocks are
compacted or cemented together.
Organic rocks
Sedimentary rock that forms from the remains of plants or animals.
Chemical rocks
Sedimentary rock that forms when minerals precipitate from a solution or
settle from a suspension.
Jack strolled along the bank of the stream. He was fascinated by the shiny glistening of
the sand. There were tiny sand grains, mud, and pebbles scattered on the bank of the stream.
Jack remembered his dad explaining that sediments were small, solid pieces of rock mixed in
with pieces of living organisms. Jack thought about how much sediments sound like
sedimentary rocks. “How are sediments and sedimentary rocks connected?” Jack wondered.
After his stroll along the steam, Jack decided to research sedimentary rocks. Jack reached or
his tablet, and began to Google sedimentary rocks. Jack read that sedimentary rocks are
formed tough a process called lithification. Lithification is a series of processes including
weathering, erosion, deposition, compaction, and cementation. Acronym: WEB2Cs.
Jack decided to investigate further. He began to read more. Weathering is the
breaking down of rocks into sediments. Sediments are tiny particles of sand, mud, and pebbles.
Erosion is the destructive forces that produce sediments. These forces include heat, cold,
water/rain, running water, wind, and ice. These agents can also carry away these sediments to
other locations. Deposition occurs when these sediments are laid down at the bottom of a lake
or ocean. Compaction occurs when the sediments are pressed together in layers as they
settle to the bottom of a lake /stream, rivers, or ocean. Cementation occurs when these
compacted layers are glued together when the crystals of minerals, dissolve in the water, act
like a glue.
Sedimentary rocks are classified according to the type of sediments that make up the
rock. Jack’s became more interested in finding out the different types of sedimentary rocks.
Jack closed his tablet and went to his dad’s library. Jack went to the reference book sections
and pulled out a text on sedimentary rocks. Jack skimmed through the table of context, until he
came to the heading, Types of Sedimentary rocks. He turned to page 235, and began to read.
There are three main types of sedimentary rocks: Clastic sedimentary rocks, organic
sedimentary rocks, and chemical sedimentary rocks.
Clastic sedimentary rocks are formed when pieces of rock fragments are cemented
together. These particle sizes vary. Common types of sedimentary rocks are shale (made from
mud, silt, or clay particles), sandstone (made from sand particles), conglomerate (made from
smooth, rounded rock particles), and breccia (made from jagged and sharp pieces of rock
particles).
Shale
Sandstone
Conglomerate
Breccia
Organic sedimentary rocks are formed from the remains of plants and animal remains
that have been cemented into the rock. “Organic” means once was part of a living thing. Plant
and animal remains include shells, bones, teeth, or plant remains. Examples of organic plants
are coal and limestone.
Coal
Limestone
Coquina
Chemical rocks are rocks that are formed when the minerals dissolve in water and then
crystallize and cement together to form the rock. Chemical rocks can also be formed when
water evaporate leaving behind minerals that crystalize and cement to form the rocks. An
example of a chemical rock is limestone.
Limestone
Jack realized that sedimentary rocks were not as strong as igneous rocks. He was
curious to know the uses of these rocks. Jack skimmed through the table of content, and found
the chapter on Uses of Sedimentary Rocks page 368. Jack began to read. Sedimentary rocks
are used to make tools like arrowhead made from flint. Sedimentary rocks are used as building
material. Sandstone and limestone are easy to cut into slabs and are used to make cement and
steel. Jack returned the reference text to the book shelf and returned to his room. Jack lay on
his bed to review what he had learned.
Jack summarizes his findings. Sedimentary rocks are classified by the type of
sediments that make up the rock. These sediments may include mud particles, sand particles,
smooth rock particles, or jagged sharp rock particles. There are three types of sedimentary
rocks. Clastic rocks made from sediments, organic rocks made from remains of plants and
animal remains, and chemical rocks made when minerals dissolve in water and crystallize to
form the rock. Sedimentary rocks are used to make weapons and building material.
Discussion Questions
1. How do geologists classify sedimentary rocks? Name the different types of sediments.
2. Differentiate between clastic, organic, and chemical sedimentary rocks.
3. Place these steps in order during the formation of a sedimentary rock: compaction,
erosion, cementation, weathering, and deposition. Write a definition for each step using
your own words.
4. What is the difference between conglomerate and breccia? Sketch a diagram of each
rock, showing the sediments that make up the rock.
Extension (Synthesis)
1. The particles of sediments that make up shale are not usually well cemented. Do you
think shale would be a good choice for building a home, especially in an area with a wet
climate? Explain your reasoning.
Resource: Geology.com
Book 2: Minerals and Rocks
Chapter 5: Metamorphic Rocks
Vocabulary Building
Metamorphic rocks
Formed from other rocks by the effect of high temperature, high
pressure, or chemical conditions different from those of the
original formation of the parent rock.
Preexisting
Already exists.
Slate
The original type of rock before it was changed.
Schist rock
A foliated rock that forms when pressure is exerted on the
sedimentary rock shale.
Gneiss
Are metamorphic. These rocks can be formed from basalt, an
igneous rock; shale, a sedimentary rock; or slate, a metamorphic
rock. Through tremendous heat and pressure, these rocks were
transformed into this new kind of rock.
Parent rock
A type of metamorphic rock that usually has ribbon-like layers.
Gneiss can often be seen on mountainsides, where rocks formed
below the surface have been pushed up by movements in the
earth's crust.
After dinner Jack decided to continue his research on metamorphic rocks. “What exactly
are metamorphic rocks and how can you classify them? Jack said to himself. Jack went in
search of his tablet. “Metamorphic sounds so much like metamorphosis,” whispered Jack in
surprise. Jack recalled in second grade that butterflies went under physical changes in the
chrysalis to become butterflies. “Maybe metamorphic rock also go through physical changes
under the crust to form”, Jack concluded. Jack decided to Google metamorphic rocks.
According to the website, metamorphic rocks can be formed from any preexisting rock,
either from an igneous rock, from a sedimentary rock, or from another metamorphic rock.
Metamorphic rocks are rocks that form deep under the Earth’s surface. Layers of rocks build up
heat from friction, and pressure from the layers of rocks above. As a result of the high heat and
pressure, chemical action can also occur. This may cause the mineral grains to change,
creating a new type of rock. Geologists classify metamorphic rocks according to the
arrangement of the mineral grains that make up the rock.
Jack read further. There are two types of metamorphic rocks: Foliated and nonFoliated metamorphic rocks. Foliated metamorphic rocks have the mineral grains arranged in
parallel layers in the rock. Well known metamorphic rocks include slate (parent shale), schist
(parent rock), and gneiss (parent rock granite). These rocks have cleavage. The rock has
cleavage if it is able to split apart along these bands.
Slate
from Shale
Schist (has lots of mica minerals)
From shale
Gneiss
from Granite
Marble
from Limestone
Jack was fascinated by the different types of metamorphic rocks. Jack continued is
research. In non foliated metamorphic rocks, the mineral grains are arranged randomly in the
rock. These rocks do not have cleavage, so they do not split into layers. They fracture in
uneven irregular pieces. Examples are quartzite ( parent rock sandstone), and marble ( parent
rock limestone). Metamorphic rocks are extremely hard.
“ What are some uses of metamorphic rocks?” Jack asked himeself.
Matamorphic rocks make good building material and sculpture. Jack laid down his tablet to
think about all the information he has learned.
Jack summarized his findings. Metamorphic rocks are hard and durable. Metamorphic
rocks are formed fromany of the three types of preexisting rocks. Metamorphic roks are formed
from heat, pressure, and chemical change in the mineral grains that make up the rock.
Metamorphic rocks are classified as foliated or non foliated, depending if the mineral grains are
arranged in parallel layers, or arranged randomly in the rock. Metamorphic rocks are formed
deep under the Earth’s surface, within the crust.
Discussion Questions
1. In your own words, write a definition for metamorphic rock.
2. How do geologists classify metamorphic rocks? Describe each type, and write an
example of each. Sketch a diagram of each.
3. Where and under what conditions do metamorphic rocks form?
Book 2: Minerals and Rocks
Chapter 6: Rock Cycle
Vocabulary Building
Rock Cycle
The process by which one rock type changes into another rock
type.
Jack enjoys riding his bike with his friends. As they rested along the stream in his back
yard, the friends decided to review for their science quiz the following day. One of the
vocabulary words for the week was the rock cycle. “What is a cycle,” asked James. “How can
we remember the definition of the rock cycle?” chimed in Paul. “Well, think of the wheels on our
bikes. The wheel go round and round in a continuous motion,” answered Jack. “The easiest
way to remember the rock cycle is to think of it has a series of processes that slowly change
one type of rock into another type. Just like the wheel of the bike spin on and one in one
continuous motion, the rock cycle is happening all the time and never stops,” jack replied.
After Jack’s friends left, he decided to research more about the rock cycle and how an
igneous rock, a sedimentary rock, or a metamorphic rock could change into each of the other
three types. Jack reached for his tablet. He Goggled rock cycle.
Jack studied the diagram above. Jack was able to interept each step in the rock cycle
diagram. For an igneous rock to form, an existing rock has to melt to form lava or magma.
The lava or magma has to be cooled and solidified on the surafce or below the Earth’s surface.
For a sedimentary rock to form, there has to be sediments. Sediments are formed by
weathering or breaking down of rocks into tiny pieces. These sediemnts are then eroded or
carried to new locations by water, wind, ice, or gravity. The sediments are deposited or placed
at the bottom of a lake, stream, river, or ocean. As the layers form, enough pressure is built to
and press the layers together until they become compacted. The mineral crystals act as a glue,
cementing the layers together to make the sedimentary rock. The entire process is called
lithification. For metamorphic rocks to form, igneous rock, sedimentary rock, or another
metamorphic rockhas to be buried deep underground. The high heat/temperature and
pressure cause the mineral grains to change. The change in the mineral grain arrangement will
form a new rock called a metamorphic rock.
Jack laid down his tablet, and summarized his findings. An igneous rock is formed when
a preexisting rock ( an igneous rock, a sedimentary rock, or a metamorphic rock) melts, cools,
and solidifies. A sedimentary rock can be formed from an igneous rock, a sedimentary rock, or
a metamorphic rock. The rock will form sediments by weathering. Sediments are then carried
to a new location by the process of erosion. The sediments are deposited at the bottom of a
lake or an ocean in layers. The pressure of the overlying layers above press or compact the
layers together. The mineral crystals in the rock, act like a glue cementing the layers together.
A sedimentary rock forms. A metamorphic rock can be formed from an igneous rock, a
sedimentary rock, or another metamorphioc rock. The rock has to be buried undergroud, where
heat and pressure cause the mineral grains to change.
Discussion Questions
1. In your own words, write a definition for the rock cycle.
2. How can a sedimentary rock change into an igneous rock?
3. How can a metamorphic rock change into another metamorphic rock?
4. How can an igneous rock change into a sedimentary rock?
Extension (Synthesis)
1. Draw the rock cycle showing all the steps in the process.