Minerals and Mohs Hardness Scale

Minerals

Unit 1, Chapter 3, Lesson 1, pg. 76

Mohs Hardness Scale

​Objective: We will identify the Mohs Hardness Scale

​Closing Task: I will apply the Mohs Hardness Scale to the real-world

Multiple Choice

Hardness, color, and luster are examples of a mineral's ___________.

• price
• weight
• property
• name

Multiple Choice

If a scientist states that a sample in the lab scored 10 on the "Mohs scale" after a scratch test, what property is she referring to for that mineral?

• It's shape.

• It's luster.

• It's texture.

• It's hardness.

Multiple Choice

How light reflects off of a mineral is called the mineral's

• luster

• streak

• cleavage

• fracture

Multiple Choice

An object that is solid, formed in nature, and has never been alive

• sand castle

• mineral

• plant

Multiple Choice

The following image shows what mineral property?

• Hardness
• Streak
• Cleavage
• Density

​What is a Mineral?

Minerals are inorganic substances. This means that minerals do NOT come from animals or plants.

​

Minerals have neatly arranged atoms and are made from very few ingredients (definite composition).

​

​You use objects made from minerals every day!

Open Ended

Where do we find the metals, metalloids and non-metals on the periodic table?

(left side, right side or middle)

Name one characteristic of each 

(Metals, Nonmetals and Metalloids)

Multiple Choice

What is a mineral?

• A type of rock formed by high heat and pressure

• inorganic substances that have neatly arranged atoms and a definite composition

• A type of rock formed by volcanoes

• A type of rock formed from sediment

Poll

What is this?

• Rock

• Mineral

• Compound

• Density

​What is an Atom?

The atom is the basic building block for everything in the universe.

​Special Features of Minerals

1.Naturally Occurring

• Not formed by humans

• Rock-forming minerals make up earth's crust.

• Examples: Quartz, Feldspar, and Olivine

​2. Definite Chemical Composition

• ​Minerals are made of only one ingredient or only a few specific ingredients.

3.​ Crystalline Form

• ​Crystals: solid substances with a regular, repeating arrangement of atoms.

• Crystals are a type of 3D shape that is found in minerals.

​Special Features of Minerals

​4. Solid

• ​Minerals are solids

• ​Solids are a type of matter with tightly packed atoms.

• ​Solids have a definite shape and volume.

​5. Inorganic

• ​Minerals are non-living. Crystals do not come from plants or animals

• ​Crystallization is the process of how crystals form

• ​When water evaporates (turns into gas) from different environments, it can leave behind solid substances that form crystals.

• ​Some sea creatures make their own crystals by filtering dissolved solids from seawater.

​Structure of Minerals

• ​Atoms in crystals are arranged in perfect patterns and form different shapes.

• ​The shape of a crystal depends on where and how it was made.

​Quartz

• ​Long, pointed crystals

Calcite

• ​Diamond-shaped or cube-shaped crystals

Multiple Choice

Is water a mineral?

• True 

• False

Open Ended

Why doesn't glass exhibit crystalline form like quartz?

​Crystal Shape

​Minerals are small and difficult to identify

​

​Under the right conditions, crystals can develop a unique shape

​

​Scientists can examine the shape of tiny crystals using scanning electron microscopes that show how atoms are arranged.

Open Ended

What can geologists infer (figure out) from the shape of a mineral?

​Common Minerals

​Common rock-forming minerals are composed of combinations of elements that are abundant in Earth's crust.

​

​Element: A pure substance made from a single type of atom.

​

​Oxygen and silicon are the most abundant elements.

​

Silicate: Types of minerals that have silicon and oxygen in their crystal structure.

​Agate

​

​When a volcano erupts, lava flows out of the volcano and hardens.

​

​When the lava cools, it forms holes.

​

These holes fill with liquid silicate and then crystallize into the mineral agate.

​Mohs Hardness Scale

• ​The Mohs Hardness Scale is used as an easy way to help identify minerals.

• ​Diamond is the hardness mineral

• ​Diamonds can scratch anything below it on the Hardness scale

• ​Talc is the weakest in terms of hardness on the scale.

• ​Talc can be scratched (broken down) by all the minerals above it.

Multiple Select

What two elements make up silicates?

• Oxygen

• Carbon

• Nitrogen

• Silicon

Multiple Choice

Diamond is the hardest mineral.

• True

• False

​How do minerals form?

​Minerals form through a process called crystallization

​

​Crystallization: when particles dissolved in a liquid turn into solid and form a crystal

​

​Minerals can crystallize from either hot or cold liquids

Multiple Choice

Which mineral is HARDER than quartz?

• Topaz, Corundum, and Diamond

• Feldspar. Apatite, and Talc

• Talc, Gypsum, Topaz

• Diamond, Calcite, Fluorite

​"Cold" Minerals

​Step 1: Water dissolves solid rock and other minerals.

​

​

​Step 2: Once water evaporates, the solids crystallize and form a new mineral.

​

Multiple Choice

Using this scale, which mineral can scratch fluorite?

• Talc 

• Gypsum 

• Apatite 

• Calcite 

​"Hot" Minerals

​Step 1. Water from earth's surface can flow through cracks in the crust and travel deep underground.

​

Step 2. When the hot water reaches a certain temperature, minerals crystallize from the hot fluid and form minerals ... such as, gold!

​

Multiple Choice

Can a penny scratch fluorite?

• Yes 

• No 

Open Ended

How does a vein of gold form?

​Stations

​1) Complete Elements, Compounds, Mixtures stations.

​

2) Schoology Make-up Test

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​3) We are almost done with the 9 weeks. Stay motivated and helpful with others and finish off the 9 weeks great!

Volcanic Minerals

​Magma: molten rock stored beneath Earth's surface.

​

Lava: when molten rock erupts near earth's surface

​

​When lava cools above ground or magma cools underground, special minerals form.

​

​Extrusive minerals: Small crystals form when lava cools quickly on or near Earths surface.

​

​Intrusive minerals: Large crystals form when magma cools slowly underground.

​Closing Task

​Changes in Minerals

​Some minerals form deep underground and are exposed to high temperature and pressure.

​

​Minerals break down when they reach earth's surface because of erosion and different weather conditions.

​

​Minerals form in special environments. For example, you cannot find the minerals quartz and olivine in the SAME rock because they are formed under different conditions (temperature and pressure).

Open Ended

Identify one way that minerals can form

Open Ended

What can you do to conserve and recycle minerals?