E. Earth and Space Systems · Rocks, Minerals, and Geological Processes

Rocks and Minerals in Everyday Life

E2.4 A3.1About 40 minutes

Learning goals

I can describe everyday uses of rocks and minerals in my home and community.
I can explain why a rock or mineral is chosen for a job, using its properties.
I can name Ontario examples, like salt from Goderich and building stone.
I can describe jobs and skilled trades that work with rocks and minerals.

Words to know

property
A feature of a material, like hardness, colour or how it breaks, that tells how it can be used.

ore
A rock with enough of a useful mineral or metal in it that people mine it.

concrete
A building material made of cement, sand, gravel and water that hardens like rock.

aggregate
Sand, gravel and crushed stone used for building roads and making concrete.

gemstone
A mineral that is cut and polished for jewellery because it is beautiful, rare or hard.

skilled trade
A job that needs special training and hands-on skills, like a stonemason, electrician or bricklayer.

A morning full of minerals

You wake up and turn on the light (copper wires). You brush your teeth (toothpaste has minerals that help scrub). You eat breakfast with a pinch of salt (halite) on your eggs, from a bowl made of clay. You walk on a concrete sidewalk (limestone and gravel) to school and write with a pencil (graphite).

Before 9 a.m., you have used dozens of rocks and minerals! Today you'll find out where they hide.

Where	Thing	Rock or mineral inside
kitchen	salt	halite
kitchen	countertop	granite, marble or quartz
kitchen	glass jars and windows	quartz sand
kitchen	dishes, mugs, bricks	clay (from weathered rock), baked hard
walls	drywall	gypsum
walls	electrical wires	copper (from copper ore)
outside	concrete sidewalk	cement (made from limestone), sand and gravel
outside	roads	crushed stone and gravel (aggregate)
outside	slate roof or stone wall	slate, limestone, granite
school	pencil	graphite mixed with clay
devices	phone, tablet, computer	many metals, like copper, gold, nickel, aluminium and lithium
winter	road salt	halite

Rocks and minerals at home and in the community

Choosing the right rock for the job

People choose a rock or mineral because of its properties:

Granite is hard and doesn't scratch easily, so it is used for countertops, steps and monuments.
Slate splits into thin, flat sheets that water can't soak through, so it makes good roof tiles.
Marble is soft enough to carve and polishes to a smooth shine, so artists use it for statues.
Graphite is soft and leaves a grey-black streak, so it is perfect for pencils.
Diamond is the hardest mineral, so it is used on saw blades and drill bits that cut rock, as well as in jewellery.
Copper carries electricity well and bends without breaking, so it is used for wires.
Halite melts ice on roads and adds flavour to food.

Close-up of a roof covered with rows of overlapping grey slate tiles. — Slate splits into thin, flat sheets that water can't soak through, which makes it a long-lasting roofing material. AI-generated image

Read each row from left to right: a rock or mineral has a property, and that property makes it right for a job.

Ontario examples

Salt: Under the town of Goderich, on Lake Huron, there is a large rock salt mine. The salt layer formed when an ancient sea dried up. Much of it becomes road salt for Canadian winters.
Nickel and copper: The Sudbury area is famous for mining nickel and copper, which are used in steel, batteries, coins and wires.
Gold: Places like Timmins and Red Lake in northern Ontario have gold mines.
Amethyst: Ontario's official mineral is mined near Thunder Bay and made into jewellery.
Sand, gravel and stone: Pits and quarries across southern Ontario supply aggregate for roads and concrete. Much of the gravel was left by the glaciers!

Jobs that use rocks and minerals

Many people work with rocks and minerals:

Geologists find and study rocks, minerals and ores.
Miners and mining engineers dig ore safely out of the ground.
Stonemasons and bricklayers build walls, steps and buildings from stone and brick. These are skilled trades.
Concrete finishers pour and smooth concrete for sidewalks and floors.
Jewellers and gemmologists cut and set gemstones.
Potters shape and bake clay into dishes.
Electricians install copper wiring.

Worked example

Let's choose a rock for a job

A town is building a new outdoor staircase in a park. It must be strong, hard to scratch and last through many freeze-thaw winters. Which is a better choice: granite or shale? Explain using properties.

List what the job needs: hard, strong, doesn't break apart easily outdoors.
Granite: hard (its quartz is 7 and its feldspar is 6 on the Mohs scale), interlocking crystals, few cracks for water to enter.
Shale: soft, splits into thin layers, crumbles easily. Water gets between layers and freeze-thaw would break it apart quickly.
Compare: granite matches all the needs.

Granite, because it is hard, strong and resists weathering. Shale is soft and splits into layers, so it would crumble outdoors.

Worked example

Let's trace a pencil back to the Earth

Where do the parts of a pencil come from?

The "lead" is not lead at all! It is graphite (a mineral) mixed with clay.
The wood comes from a tree.
The metal band that holds the eraser is often aluminium, made from an ore called bauxite.
The eraser is usually made of rubber or plastic.

A pencil uses at least two minerals or rock materials (graphite and clay) and a metal from an ore.

A pencil comes from the Earth too: the graphite and clay core is made of minerals, and the metal band is made from an ore.

Safety

Don't taste anything during the scavenger hunt, even salt, unless a grown-up says it is food. Don't take apart electronics or batteries. Ask a grown-up before touching cleaning products: some contain minerals, but they are not safe to handle.

Just for fun

Next time someone at dinner says "Please pass the salt," try saying, "Here's your halite!" You'll sound just like a geologist (and maybe confuse everyone).

Hands-on activity

Mineral scavenger hunt

You need: paper, a pencil, a clipboard or hard book to write on.

Make a chart: Room, Object, Rock or mineral inside, Why it was chosen (property).
With a grown-up, walk through your home. Find at least 10 things made with rocks or minerals. Use the table in this lesson to help. Don't forget: windows, mirrors, salt shaker, mugs, a brick or concrete wall, the pencil you are holding, coins, a ring.
For each object, write a property that makes the material useful (hard, shiny, carries electricity, can be carved, melts ice...).
Go outside (with a grown-up) and find 3 more: sidewalk, gravel, a stone wall, a rock garden.
Pick your favourite object and draw a picture showing its journey from the ground to your home.
Talk about it: What job does someone do to get this material to you? (For example: miner, truck driver, stonemason.)

Your turn

Name three things in your home made with rocks or minerals.

What mineral is in a pencil?

Why is slate used for roofs?

Why is copper used for wires?

What Ontario town has a big salt mine under Lake Huron?

What is concrete made from?

Name a skilled trade that works with stone.

More practice: warm-up

What mineral is used to make glass?

What mineral is in drywall?

Which mineral do we put on icy roads?

What is Ontario's official mineral, used in jewellery?

What do we call sand, gravel and crushed stone used for roads?

More practice: on your own

Why is marble a good rock for statues?

Why are diamonds used on saw blades that cut stone?

Why would talc (Mohs 1) be a bad choice for a kitchen countertop?

Why does Ontario have so much gravel for building?

Your phone has many metals. Name two and say what Ontario city is known for mining one of them.

Challenge

A builder needs a material for a garden path that lets rain soak through into the soil. Would you choose a concrete slab or loose gravel? Why?

Choose one everyday object and describe its journey from the ground to your home. Name at least two jobs along the way.

Road salt melts ice and keeps people safe. In Grade 3 you learned it can also harm soil and plants. How could a town use salt wisely?

Check your understanding

Quiz

Which mineral is in a pencil?

Glass is made mostly from...

Why is granite used for countertops?

Copper is used in wires because it...

Which Ontario town has a large salt mine?

A stonemason...

For parents and teachers

Big idea (E2.4): Rocks and minerals are everywhere in daily life, and each is chosen for its properties (hardness, cleavage, conductivity, carvability). Many careers and skilled trades depend on them (A3.1).

How to help: The scavenger hunt works best with an adult asking "Why do you think they used that?" Look at building materials on a walk (brick, limestone, granite steps, slate). If you know someone who works in mining, construction or a trade, a short conversation is a great real-world connection.

Common difficulties:

Not seeing processed materials as minerals. Glass, concrete and metal wires all began as rocks or ores.
Thinking pencil lead is the metal lead. It is graphite and clay.
Describing why a material is used with "it's good". Push for a specific property.

Safety: No tasting, no taking apart electronics or batteries, and adults handle cleaning products.