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Did you know that every time you take a shower, drink clean water, flip on the lights, open the fridge, drive to school, stop at a stoplight, take the bus, fly on vacation, or toss your soda can in the recycling bin, there was a civil engineer involved somehow?

We’re going to learn what it’s really like to be a civil engineer, how the field of civil engineering started, and how it’s absolutely everywhere you look.

This course is really a sneak peek into the career life of different types of work civil engineers actually do, and it’s meant for students grades K-12 who are interested in learning about what types of science and engineering jobs are out there.

A civil engineer designs and builds public works: bridges, dams, roads, and buildings, airports, tunnels, and systems for water supply and sewage treatment. It’s actually one of the oldest branches of engineering. When people first starting living in permanent settlements like cities, they started to shape their environment to what they needed.

We’re going to look at ancient and modern civil engineers and their projects, learn what a civil engineer does with their day, and how you can get started being a civil engineer today!

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We’re going to cover the following scientific concepts:

Bridges	Civil Engineering Challenges
Buildings	Ancient and Modern Structures
Skyscrapers	Tension & Compression
Dams	Building Materials
Roads	Real Engineering Projects
Water Supply	Different Types of Engineers

Step 1:

To get started learning, print out this workbook, which includes a complete shopping list inside. You’ll be filling out this workbook out as you work through the course.

Step 2:

Watch the videos below in order. If you have the materials to do the experiments, feel free to do the experiments along with me. If not, just watch the videos so you still get the experience of what the experiment is all about. Some of the experiments have additional worksheets you can print out and fill in as you work through the experiment.

Lesson 1: American Society of Civil Engineers
Lesson 2: What Does a Civil Engineer Do?
Lesson 3: Civil Engineering Projects
Lesson 4: Tension & Compression
Lesson 5: Breaking Point
Lesson 6: Building Materials
Lesson 7: Color streak
Lesson 8: Moh’s Hardness
Lesson 9: Cleavage & Fracture
Lesson 10: Acid Test
Lesson 11: Sedimentary, Metamorphic, and Igneous Rocks
Lesson 12: Tenacity
Lesson 13: Luster
Lesson 14: Magnetism
Lesson 15: Density
Lesson 16: Geology Field Trip

Quick Links:
Civil Engineering 2
Civil Engineering 3

Lesson 1: American Society of Civil Engineers

Lesson 2: What Does a Civil Engineer Do?

Lesson 3: Civil Engineering Projects

Lesson 4: Tension & Compression

Tension is when things get pulled apart. Compression is when things get squashed together. If you’ve ever teetered on the edge of a diving board, you know that the board flexes under your weight. The heavier you are, the more it bends. The top of the board gets slightly stretched further than the normal length (tension) while the underside gets slightly shorter (compressed). So the top of the board experiences tension and the underside compression.

Lesson 5: Breaking Point

If you’ve ever teetered on the edge of a diving board, you know that the board flexes under your weight. The heavier you are, the more it bends. The top of the board gets slightly stretched further than the normal length (tension) while the underside gets slightly shorter (compressed). We’re going to duplicate this without needing to visit the pool.

We’re going to expand on the topic covered in the Tension and Compression section of this article. All you need for this experiment is:

a pencil or a craft stick that you don’t mind breaking
a pair of hands

1. Grab the pencil or the craft stick with one hand on one end of the object and the other hand on the opposite end.

2. Bend the pencil or craft stick a bit, but not too far….yet. Notice how you can bend it quite a bit without it breaking.

3. Now, feel free to bend it slowly until it breaks.

You have just played with tension, compression and elasticity. When you bent the pencil it had no problem going back to its original shape right? Wood is fairly elastic, meaning it can bend quite a bit before breaking. This comes in quite handy if you happen to be a tree, since you can bend in the wind which allows you to survive most storms without breaking.

Now, let’s look at tension and compression. If you look at the pencil or craft stick that you just broke you may notice that one side of the break may look different then the other side. Tension is when things get pulled apart. Compression is when things get squashed together.

If you bent your pencil towards the ground for example, the molecules along the top of the pencil were pulled apart, and the molecules along the bottom were squashed together. If you didn’t bend too far they just went back to normal when you stopped applying force. However if you bent too far, “SNAP”, the pencil broke in two! Just like objects have an elastic limit that if you go beyond it you will break it, things also have a tension and compression limit. Pull something or push something too far, and you’ll break it.

Lesson 6: Building Materials

What your building is made out of is just as important as how you build it because that’s part of the design!

Lesson 7: Color streak

You will be able to identify minerals by their colors and streaks, and be able to tell a sample of real gold from the fake look-alike called pyrite.

Materials

1 handheld magnifying lens
Unglazed porcelain tile
Rock samples (the ones in the video are: graphite, pyrite, talc, iron, and jasper)

Download worksheet and exercises

Every mineral has a set of unique characteristics that geologists use to test and identify them. Some of those tests include looking at the color of the surface, seeing if the mineral is attracted to a magnet, dripping weak acids on the rock to see if they chemically react, exposing them to different wavelengths of light to see how they respond, scratching the rocks with different kinds of materials to see which is harder, and many more. There are more than 2,000 different types of minerals and each is unique. Some are very hard like diamonds, others come in every color of the rainbow, like quartz and calcite, and others are very brittle like sulfur.

The color test is as simple as it sounds: Geologists look at the color and record it along with the identification number they’ve assigned to their mineral or rock. They also note if the color comes off in their hands (like hematite). This works well for minerals that are all one color, but it’s tricky for multi-colored minerals. For example, azurite is always blue no matter where you look. But quartz can be colorless, purple, rose, smoky, milky, and citrine (yellow).

Also, some minerals look different on the surface, but are really the same chemical composition. For example, calcite comes in many different colors, so surface color isn’t always the best way to tell which mineral is which. So geologists also use a “streak test”.

For a streak test, a mineral is used like a pencil and scratched across the surface of a ceramic tile (called a streak plate). The mineral makes a color that is unique for that mineral. For example, pink calcite and white calcite both leave the same color streak, as does hematite that comes in metallic silvery gray color and also deep red. This works because when the mineral, when scratched, is ground into a powder. All varieties of a given mineral have the same color streak, even if their surface colors vary. For example, hematite exists in two very different colors when dug up, but both varieties will leave a red streak. Pyrite, which looks a lot like real gold, leaves a black streak, while gold will leave a golden streak.

The tile is rough, hard, and white so it shows colors well. However, some minerals are harder than the mineral plate, like quartz and topaz, and you’ll just get a scratch on the plate, not a streak.

Number your rock samples by placing them on your data table.
Using your data table, record the color of each sample.
Now use your streak plate. Take a rock and draw a short line across your streak plate (unglazed porcelain tile).
Record the color of the streak in your data table. Are there any surprises?

Exercises

What does it mean if there’s no streak left?
Give an example of a kind of rock that leaves a streak a different color than its surface color.
What is a mineral that appears in two different colors, yet leaves the same color streak?

Lesson 8: Moh’s Hardness

By the end of this lab, you will be able to line up rocks according to how hard they are by using a specific scale. The scale goes from 1 to 10, with 10 being the hardest minerals.

Materials

Steel nail
Penny
Small plate of glass (optional)
Rock samples (minerals in the video: talc, selenite, calcite, fluorite, apatite, feldspar, quartz)

Download worksheet and exercises
The sample’s hardness is determined by trying to scratch and be scratched by known materials, like pennies, steel, glass, and so forth. If the material leaves a mark on the mineral, then we know that the material is harder than the mineral is. We first start with a fingernail since it’s easy to use and very accessible. If it leaves a mark, that means that your fingernail is harder than the mineral and you know it’s pretty soft. Talc is one of the softest minerals, making it easy to scratch with your fingernail.

However, most minerals can’t be scratched with a fingernail, so we can try other objects, like copper pennies (which have a hardness of 2.5-3.5), steel nail (3.5-5.5), steel knife (5.5), and even quartz (7). The most difficult part of this experiment is keeping track of everything, so it’s a great opportunity to practice going slowly and recording your observations for each sample as you go along.

Number your samples on the data table and place each rock on the table. If you have the same samples listed above, you can scratch each rock with every other rock to find where they are on the Mohs’ Hardness Scale, where 1 is the softest and 10 is the hardest:
Mohs’ Scale of Hardness Talc

Selenite
Calcite
Fluorite
Apatite
Feldspar
Quartz
Topaz
Corundum
Diamond

If you don’t have one of each from the following scale (at least up to quartz), then you’ll need to do this experiment a different way – the way most geologists do it in the field. Here’s how:
Scratch one of the rocks with your fingernail. If you can leave a mark, then write “Y” in the second column of the data table. Now skip over to the last column and estimate the hardness to be less than 2.5.
If you can’t scratch it with your fingernail, try using the mineral to scratch a copper penny. If it doesn’t leave a mark on the penny, skip over to the last column and estimate the hardness to be between 2.5-3.5.
If it does leave a scratch on the penny, then try scratching the mineral with a steel nail. If the nail leaves a scratch, skip over to the last column and estimate the hardness between 3.5-5.5.
If you can’t scratch the sample with the nail, see if the mineral can make a scratch on the plate glass. Glass has a hardness of 6-7. If it doesn’t make a scratch on the glass, then it’s between 5.5-6.5. If it does, it’s higher than 6.5. For example quartz will make a scratch on the plate, and its hardness has been recorded at 7.

Exercises

If a mineral scratches a penny but doesn’t get scratched by a nail, can you approximate its hardness?
Give examples of the hardest and softest minerals on the Mohs’ Scale.
Is feldspar harder or softer than quartz?

Lesson 9: Cleavage & Fracture

Today, you’ll learn what to look for in a broken mineral. There are different names for the types of breaks that a mineral can experience. You’ll need to ask a few important questions during your investigation, like, “What is the difference between mineral cleavage and fracture?”

Materials

Mineral samples
Hand lens
Good lighting

Download worksheet and exercises

Cleavage and fractures are two properties that geologists test at the same time, both by observations. Using a hammer, geologists will break a mineral by studying how the mineral broke. They describe the way the surfaces look. Sometimes minerals break apart like they were stacked together in thin sheets. Other times they break off in large chunks, and the sides of each chunk are always at right angles. The way that they break into planes is called “cleavage.” Minerals can have cleavage in one direction, like mica, or two or three directions (like halite). The type of cleavage is also described using geometric terms. Halite has cubic cleavage because when it breaks, it looks like it’s made up of tiny cubes, while calcite has rhombic cleavage because it never breaks into right angles, but always in a rhombus, or diamond shape.

Fracture describes the surfaces that are broken but don’t break along plane lines. A mineral can have both cleavage and fracture, and some have either one or the other. Quartz has no cleavage, only fracture. Calcite has no fracture, only cleavage. Feldspar has both.

Geologist look for smooth surfaces, which can be (when viewed up close) cubes, triangles, or simple, flat plane surfaces. Always look for cleavage first, then fracture when making your data observations.

An easy way to look for cleavage is to hold the sample in sunlight and look for surfaces that reflect light and describe the surface in one of three ways for cleavage:

Perfect – the mineral breaks to reflect a clear, glass, or mirror-smooth surface.
Good – the mineral breaks to reveal a surface that reflects light, but may be dull in places.
Poor – the mineral breaks along clear planes and flat spaces are visible, but these are dull and could be ragged, and not very reflective.

Remember, a mineral can have more than one cleavage plane. For example, feldspar has two cleavages, one which is perfect and one which ranges from poor to good, depending on the sample. At first glance, you might not be able to tell feldspar from quartz, but if you look for cleavage, you’ll find feldspar has two planes of cleavage whereas quartz has none. Quartz will look like lots of broken surfaces that are not flat planes.

The way a mineral breaks depends on what the crystalline structure looks like. Here are some forms of cleavage:

Basal cleavage is cleavage on the horizontal plane, like mica. Basal cleavage samples can sometimes have their layers peeled away.
Cubic cleavage is found in mineral that have crystals that look like cubes., like with galena or halite.
Octahedral cleavage is found on crystals that have eight-sided crystals, like two pyramids with their bases stuck together. Look for flat, triangular wedges that peel off an octahedron, like in the mineral fluorite.
Prismatic cleavage is found in minerals that have four or more sides and are long in one direction, like aegirine, where the crystal cleaves on the vertical plane.
Rhombohedral cleavage is really my favorite, because it shows up in calcite so well due to its internal crystal structure, which is made up of hexagonal crystals. No matter where you look, there are no right angles to this cleavage – everything is at an angle.

Fracture can be described like this:

Conchoidal (like a shell, for example: obsidian)
Earthy (looks like freshly broken soil, like limonite)
Hackly or jagged (when a mineral is torn, like with naturally occurring silver or copper)
Splintery (looks like sharp, long fibrous points, like chrysolite)
Uneven (rough surface with random irregularities, like pyrite and magnetite)
Even or smooth (the fracture forms a smooth surface)

You will begin by labeling each of the mineral samples, starting with 1. Make sure to keep track of these samples throughout the entire lab.
Take the mineral samples and note which number it is on your observation data sheet.
Using your hand lens, look carefully for little sparkles of surfaces that reflect light. These are the cleavage surfaces.
In the space marked cleavage on your worksheet, label the cleavage as perfect, good, or poor. If there are no flat surfaces that are broken, write “none.” Some of your samples may have more than one cleavage. Make a note if this is the case.
Now look for broken surfaces that are not flat. Place a check below the best category of fracture that the mineral shows. If there are no surfaces like this, mark “none.” If you are uncertain about either category, leave the section blank. It is better to record no information than to mark something that can mess up your data.

Exercises

Which properties do geologists look for when they try to categorize a mineral? Circle all that apply.
1. Color
2. Shine
3. Smell
4. How it breaks
If you break a sample of quartz and find that it has no clean surfaces of separation, what kind of cleavage does it show?
True or false: A mineral can show more than one type of cleavage or fracture.
What is a fracture called that is similar to glass?

Lesson 10: Acid Test

Your goal is to identify samples according to their reactivity with acid. Minerals that react are called chemical rocks, and minerals that don’t are called clastic rocks. Some chemical rocks contain carbonate minerals, like limestone, dolomite, and marble which react with the acid.

Materials

Acetic acid (plain distilled white vinegar) in a dropper bottle or in a small cup with a medicine dropper
Pie tin
Paper towels
Steel nail
Optional: handheld magnifier
Rock samples (in the video: bituminous coal, limestone, conglomerate, coquina, shale, siltstone, sandstone, and dolomite)

Download worksheet and exercises
If your sample fizzed, you’ve got carbonate in your sample, and your sample might be calcite, marble, coquina, or limestone. If the powder fizzed, you’ve probably found dolomite, which is similar to calcite except it also has magnesium, which bonds more tightly than calcium, making the sample less reactive than limestone.

The reaction doesn’t always occur quickly. Sometimes you’ve got to be patient and wait. For example, magnesite has a weak reaction with acid, and if you grind it to a powder and then test, you have to wait half a minute for tiny bubbles to form. Magnifiers are helpful for these smaller, weaker reactions.

A lot of rocks contain small amounts of calcite or other carbonate minerals, so all of these make a fizz even though carbonate is only a small part of the rock. There might be small veins or crystals of carbonate minerals that you can’t even see, yet when you place a drop of acid on them, they bubble up. You can tell these types of rocks from the real thing because you won’t be able to do more than one acid test on them. The second time you try to add a drop of acid, there will be no reaction. The acid test is just one of many tests used, and shouldn’t be the only one that you use to determine your sample’s identification.

Chemically speaking, when you add the acid to the samples, you’re dissolving the calcium in the samples and releasing carbon dioxide gas into the air (these are the bubbles you see during the reaction).

For calcium carbonate and vinegar, the reaction looks like this:

2CH₃COOH + CaCO₃ → Ca(CH₃COO)₂ + H₂O + CO₂

The first term on the left CH₃COOH is the acetic acid (vinegar), and the second term CaCO₃ is the calcium carbonate. They both combine to give water H₂O, carbon dioxide CO₂, and calcium acetate Ca(CH3COO)₂ .

Carbonate minerals that react with acid (either vinegar or hydrochloric acid (HCl) as shown in the video) include aragonite, azurite, calcite, dolomite, magnesite, malachite, rhodochrosite, siderite, smithsonite, strontianite, and witherite. You can increase the reactivity with HCl by warming the HCl solution before using for the acid test.

You can do this experiment in other ways, too! Place a piece of chalk in a cup of vinegar and watch the tiny bubbles form on the chalk. This also works for egg shells, because they also contains calcium.

Do not let kids test their minerals with hydrochloric acid.

(For teachers demonstrating the HCl version of this test: CaCO3 + 2HCl → Ca++ + 2Cl–+ H2O + CO2)

Note: a few rocks, like coquina, oolite, and tufa can produce an extreme reaction with hydrochloric acid because they have a lot of calcite, and/or a lot of pore space that allows for high surface areas (exposing more of the calcium carbonate to the acid). The reaction will be quick, foamy, and vigorous, which is why we only use one drop of acid at a time.

Number and label your samples using the data table.
Use a dropper to take vinegar out of its bottle.
Drop a few drops onto your sample and watch for a reaction. You’re looking for bubbles, both in size and quantity. A few tiny bubbles don’t count. You’re looking for a reaction similar to the baking soda and vinegar reaction you are probably familiar with.
Optional: check with your hand lens while the reaction is taking place.
Record your observations in your data table.
Wipe your samples dry with a clean, damp cloth.
Test the hardness of your sample with the nail and record it in your data table. If the sample is softer than the nail, you’ll see a scratch and a powder left behind. Scratch it a couple of times to dig up more powder, then add a drop of the vinegar to the powder. Record your results. Did you see bubbles on the powder?

Do not let kids test their minerals with hydrochloric acid. (For teachers demonstrating the HCl version of this test: CaCO₃ + 2HCl → Ca⁺⁺ + 2Cl^—+ H₂O + CO₂) Note: a few rocks, like coquina, oolite, and tufa can produce an extreme reaction with hydrochloric acid because they have a lot of calcite, and/or a lot of pore space that allows for high surface areas (exposing more of the calcium carbonate to the acid). The reaction will be quick, foamy, and vigorous, which is why we only use one drop of acid at a time. Exercises

What state(s) of matter is/are present during the chemical reaction of the acid test?
Write the chemical equation that describes the reaction using your own words. For example, to make water, you’d write: oxygen + hydrogen = water. What would you write for the reaction on the rocks?

Lesson 11: Sedimentary, Metamorphic, and Igneous Rocks

Clastic rocks come in very different shapes and sizes, but they all have a few characteristics in common. A clast is a grain of sand, gravel, pebble, etc that makes up a rock. Clastic rocks look like they are made up of fragments of other rocks.

Materials

Small piece of plate glass
Magnifying lens
Vinegar
Paper towel
Shallow dish
Rock samples (in the video: bituminous coal, sandstone, siltstone, shale)

Metamorphic rocks are classified by as being foliated or non-foliated. Foliated rocks have layers, like bands around the rock. Non-foliated rocks don’t have any layers are are solid-looking throughout, although they might have crystals here and there. If the crystals are aligned to form a layer, then it’s a foliated rock.

Igneous rocks are classified as being extrusive or intrusive. An intrusive rock has a courser grain texture without a magnifier. Extrusive rocks need a magnifier to see the finer grains that make up the rock. Some extrusive rocks, like obsidian, need a microscope to see the fine grains.

Download worksheet and exercises

Clastic sedimentary rocks are fragments of other rocks. Geologists look at the tiny particle grains that make up the rock when they name the rock. For example, mudstone is named for its tiny particles of mud and clay, and sandstone is made up of larger grains of sand. The conglomerate rocks look like they are made up of pebbles. Siltstone under a strong magnifier show microscopic grains.

Number and label your samples with your data table.
Take your hand magnifier and look closely at each sample and record the color information on the data table.
Use a dropper to take vinegar out of its bottle.
Drop a few drops onto your sample and watch for a reaction. If you see a reaction, note this in the data table and classify the rock as a chemical rock, not a clastic rock.
Wipe your samples dry with a clean, damp cloth.
Test the hardness of your sample with the nail and record it in your data table using Mohs’ Hardness Scale.

Exercises

Give three types of clastic sedimentary rocks.
How can you tell a clastic from a non-clastic rock?
Does hardness determine a clastic rock? If so, what hardness do you expect a clastic rock to have?

Lesson 12: Tenacity

Tenacity is a measure of how resistive a mineral is to breaking, bending, or being crushed. When you exceed that limit, fracture is how the mineral breaks once the tenacity (or tenacious) limit has been exceeded.

Materials

Hammer (if your piece of coal is large)
Rock samples (in the video: copper, mica, selenite, sulfur)

Download worksheet and exercises
Tenacity is a measure of how a mineral behaves when under stress, like being crushed, bent, torn, or hammered. Minerals will react differently to each type of stress. Minerals can have more than one type of tenacity, since it’s possible for a mineral to have different (or several at the same time) reactions to the stress. Here’s a way to classify their response to stress:

Brittle: The sample crumbles or turns into a powder. Most minerals are brittle, like quartz.
Sectile: These minerals can be separated with a knife, like wax, like gypsum.
Malleable: When you hammer the mineral and it flattens instead of breaks, it’s malleable like silver and copper.
Ductile: A mineral that can be stretched into a wire is called ductile. All true metals are ductile, like copper and gold.
Flexible-Inelastic: When you bend a mineral and release it, it stays in the new shape. It was flexible enough to bend, but it didn’t snap back into its original shape when released, like copper.
Flexible-Elastic: When you bend a mineral and release it, it springs back into its original shape. Minerals that are flexible-elastic are fibrous, like chrysotile serpentine.

Label and number each of your samples with your data table.
Use a hammer and try to break the copper sample. Make sure you do this on a hard surface (like the concrete) so you don’t damage your floor or table!
To test for brittleness, like for sulfur, do a scratch test to see if it leaves a fine powder. Use your streak plate if you think your specimen has a hardness of less than 7.
For sectile tenacity, like with mica, carefully insert a knife into the mineral to see if it goes through. If the knife can penetrate through the sample (be careful with this!), then it’s sectile.
To check for flexibility, like mica and selenite, use only slight pressure so you don’t break your sample. Notice if the sample springs back or retains its new shape when released.
Complete the data table with your observations.

Exercises

What are four different types of tenacity?
How is elastic different from inelastic tenacity?
How many types of tenacity can a mineral have?

Lesson 13: Luster

Luster is the way a mineral reflects light, and it depends on the surface reflectivity.

Materials

Sunlight
Rock samples (in the video: pyrite, fluorite, and serpentine)

Download worksheet and exercises

Every mineral has a particular luster, but some have different luster on different samples. Since it’s gauged by eye and not a scientific instrument, there’s quite a lot to be left to the observer when describing it. Luster is not usually used to identify minerals, since it’s so subjective.

That said, it is useful when describing a sample’s surface, so hold up yours to the light and use the descriptions below to find the one that best describes what you see.

Metallic or splendent luster are found in highly reflective minerals, like gold.
Submetallic luster is found in minerals that have a similar luster to metal, but it’s a bit duller and less reflective. These minerals are opaque and reflect light well. You’ll find submetallic luster in the thin splinter sections of minerals, such as sphalerite, cinnabar, and cuprite.
Vitreous or glassy luster describes 70% of all minerals, and they have the luster of glass. Quartz, calcite, topaz, beryl, tourmaline, and fluorite are examples of glassy luster.
Adamantine lusters (brilliant, like a cut diamond) are for transparent materials that show a very bright shine because they have a high refractive index.
Resinous lusters are usually yellow, orange, or brown minerals that have high refractive indices (like the way sunlight goes through honey).
Silky lusters have very fine fibers aligned in parallel, so it looks like a cloth of silk. Minerals like asbestos, ulexite, and a variety of gypsum called satin spar all have silky luster. If a sample has fibrous luster, it is coarser than a silky luster.
Pearly luster minerals look like the way light reflects off pearls, like the inside an oyster shell. These types of minerals have perfect cleavage, like muscovite and stilbite. Mica also has a pearly luster. Some pearly luster minerals also have an iridescent hue.
Greasy or oily luster looks like fat, and is found in minerals that have a lot of microscopic inclusions, like opal and cordierite. Most greasy luster minerals also feel oily.
Pitchy luster looks a lot like tar, and is found in radioactive minerals.
Waxy luster resembles wax, the way jade and chalcedony look on their surface.
Dull or earthy luster minerals have very little or no luster at all, because they have a surface that scatters the light in all directions, like with Kaolinite. Some geologists say that earthy luster means less luster than dull, but it’s really a close call between the two.

When light strikes a surface, it can be reflected off the surface, like a mirror, or it can pass through, like a window, or both. Metallic luster has most of the light bouncing off the surface, whereas calcite has most passing through the mineral. When light travels through a mineral, it refracts, or changes speed, as it crosses the new material boundary. This is what makes the luster appear different for different materials.

Refraction is how light bends when it travels from one substance to another. When light moves through a prism, it bends, and the amount that it bends is seen as color that comes out the other side. Each color represents a different amount of bending that it went through as it traveled through the prism.

Label and number each of your samples and record this on your data table.
Hold your mineral in the sunlight.
Use the list to find the word that best describes what you see. Look particularly on your sample for a surface that is clean and not tarnished, discolored, or coated. Look at cleaved surfaces and on uneven parts.

Metallic
Submetallic (duller than metallic)
Vitreous or glassy
Adamantine (like a cut diamond)
Resinous (like honey)
Silky (like a silk cloth)

Pearly
Greasy or oily
Pitchy (like tar)
Waxy (like a candle)
Dull or earthy

Record your observations in the data table.

Exercises

What is refraction?
Feldspar has perfect cleavage on two surfaces but fractured on a third. What kind of luster would you say it has?
What type of luster is found on mica?

Lesson 14: Magnetism

A magnetic field is the area around a magnet or an electrical current that attracts or repels objects that are placed in the field. The closer the object is to the magnet, the more powerfully it’s going to experience the magnetic effect. Nearly all minerals that are magnetic have iron as a component.

Materials:

Magnet
Rock samples (samples in the video that stuck to the magnet are lodestone [which is the magnetic form of magnetite] and meteorites)

Download worksheet and exercises
Minerals can become attracted to a magnetic field if they are heated to a certain temperature. These minerals become ferromagnetic after heating them up. Some minerals also act as magnets when they are heated, but this effect is only temporary for as long as the mineral stays at that temperature.

Magnetism is a very useful way of identifying a mineral, because it’s so precise. When testing for magnetism, you’ll get better results if you use the strongest magnet you can find. You’ll find minerals that respond to magnets (without heating them up first) are metallic-looking samples.

Most student-grade geology books refer to minerals that are attracted to magnetic fields as “magnetic,” which leads to confusion because there’s a difference between being “magnetic” (acting as a magnetic field) and being “attracted to magnetic fields.” When you fill out your observations in the data table, keep this in mind when you write down what you see by using the words “magnetic” or “attracted to a magnetic field.”

Label and number each of your samples and record this on your data table.
Hold your mineral close to the magnet and observe how strongly it is attracted to the magnet. How far away do you have to be to start influencing the sample?
Complete the data table.
There are several magnetic properties that geologists use to specify the type of magnetism within a mineral:
- Ferromagnetism is the kind of magnetism you’ll see in magnetite and pyrrhotite, as these have strong attraction to magnetic fields.
- Paramagnetism is a weak attraction to magnetic fields, such as with the minerals hematite and franklinite.
- Diamagnetism occurs in only one mineral, bismuth, which means it’s repelled from magnetic fields.
- Magnetism is found in only one mineral called lodestone, which is the magnetic version of magnetite. It’s really rare, since it’s only found in a couple locations in the entire world. Lodestone is weakly magnetic, but if you drop small paperclips, staples, and iron filings onto a piece, they’ll stick.

Exercises

Is lodestone the same as magnetite?
Which mineral is repelled from any magnetic field?
Which element is usually present in minerals that have magnetic properties?

Lesson 15: Density

Density can be found by weighing an object and dividing by the volume of the object, and for geologists, is the same thing as specific gravity. Water has a density of 1, which means that 1 gram of water takes up 1 cubic centimeter of space. Specific gravity is a number you get when you divide the density of an object by the density of water, which happens to be 1 gram/cm3.

Materials

Measuring cup that has graduation marks for milliliters (mL)
Scale that measures in grams
Rock samples (in the video: quartz, meteorite, pumice)

Download worksheet and exercises

The specific gravity (also called the “s.g.” or “SG”) of a mineral or rock is how we compare the weight of the sample with the weight of an equal volume of water. Low specific gravity substances, like pumice (0.9), are not very dense. High specific gravity substances, like for gold (19.3), are very dense. If the specific gravity is less than 1, it will float on water.

Density is a way to measure two different minerals that might be exactly the same size, but their weights are different. Minerals with a metallic luster tend to be heavier. You’ll find variations for SG within the same minerals due to impurities of the mineral. Along those lines, this test can’t be done for material that is embedded within a rock, only for a single sample.

Here are a few examples for you to compare your samples with:

Amber 1.1
Quartz 1.5
Obsidian 2.5
Amethyst 2.6
Diamond 3.5
Hematite 5.05
Pyrite 5.1
Gold 19.3

Label and number each of your samples and record this on your data table.
Weigh each sample and record the information on your table.
Fill your cup with water and note the level.
Completely submerge your sample and read the new water height.
Subtract #4 from #3 answers to get the amount of water your sample displaces. Record this in your data table.
Find the volume of water displaced for every sample.
Divide the mass of the object by the volume to find the density: ρ = m / V with the units of grams / mL
Note: 1 mL = 1 cm³

Exercises

In your data table, which number was the same for every trial run?
What is the equation for finding density?
How did you find the volume of the rock?

Lesson 16: Geology Field Trip

Field trip time! Today you get to sift through sand and excavate your rock samples right on your own desk. This inexpensive set of rock samples contain pieces of not only fossils and gems, but true minerals and rocks also, so take your time and follow the video instructions carefully.

Materials:

“Geology Field Trip” rock samples: dinosaur bone, horn coral, gastropod, brachiopod, trilobite, oyster, shark’s tooth, petrified wood, crinoid stem, pyrite, magnetite, gypsum, hematite, sulfur, pumice, selenite, limonite, quartz, mica, fluorite, calcite, feldspar, coal, red sandstone, conglomerate, obsidian, scoria, mica schist, quartzite, shale, gneiss, turquenite, rock crystal, agate, and amethyst.
Penny
Nail
Streak plate
Glass plate
Water in a graduated container
Sunlight
Pencil and paper
Handheld magnifier

Download worksheet and exercises
NEW! I’ve improved the worksheet, so you can download the latest edition here.

You’re first going to classify your pile of rocks right along with the instructional step–by-step video. So fire up the video and get your materials out as you complete the data table.
Use the table on the next page to place your rocks once you’ve identified them. Enjoy your second real geologist rock hunt

dinosaur bone
horn coral
gastropod
brachiopod
trilobite
oyster
shark’s tooth
petrified wood
crinoid stem
pyrite
magnetite
gypsum

hematite
sulfur
pumice
selenite
limonite
quartz
mica
fluorite
calcite
feldspar
coal
red sandstone

conglomerate
obsidian
scoria
mica schist
quartzite
shale
gneiss
turquenite
rock crystal
agate
amethyst

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