Minerals

EQ:How are minerals a part of

rocks?

What is a Mineral?DEF: A naturally occurring, inorganic solid that has a crystal structure & a definite chemical composition.

Example: Quartz

Naturally-occurring

Never man-made

Ex: Like rocks

Inorganic: Means the mineral cannot

come from things that were once living

Non Example: Coal – it is organic because it comes from plants that lived millions of years ago.

Solid

A 3-D geometric figure

Not a liquid or a gas!

Crystal: The repeating pattern of particles, line up when they form

Like a snowflake pattern or rock candy

6 Different Crystal Systems: Cubic Ex: Magnetite Hexagonal Ex: Quartz Tetragonal Ex: Rutile Orthorhombic Ex: Sulfur Monoclinic Ex: Azurite Triclinic Ex: Microcline

Feldspar

Definite Chemical Composition Certain elements form

together in specific ways

Like Hydrogen & Oxygen (H2O) and Carbon & Oxygen (CO2) form together to make these compounds

Physical Properties Identify Minerals

Physical Properties include 6 “tests” you can perform on minerals to determine what type of mineral they might be.

1. Streak Test

The color of the mineral’s powder that’s left behind when it is rubbed across a rough surface

Example: Pyrite looks like gold but, it’s streak looks greenish-black (aka “fool’s gold”)

2. Luster

Describes how light is reflected from the mineral’s surface. What does it look like?

3. Density

4. Cleavage

One way minerals break Easily split along flat surfaces

Ex: Mica & Feldspar

5. Fracture One way minerals break Break unevenly in irregular

ways

Chipped Shell-like Ex: Quartz Jagged points Ex: Copper

& Iron Crumbles Ex: Clay

6. Mohs Hardness Scale A scale that ranks 10 minerals from

softest to hardest. You can compare unknown minerals to the minerals on this scale Hardness can be tested by a Scratch

Test A mineral can scratch any other softer

mineral It can also BE scratched by any

harder mineral

Softest Mineral – TalcHardest Mineral - Diamond

Science StandardS6E5. How Earth’s surface forms

b. Minerals make rocks EX: Granite may be made of many different

minerals (feldspar, mica, hornblende, quartz) c. Rocks are classified by how they are

formed EX: Igneous rocks form from magma/lava

cooling d. Different processes change rock & the

surface of the Earth EX: Weathering & Erosion break down rocks

& move them to new places

Types of Luster

Metallic Ex: Galena Glassy Ex: Topaz Waxy, Greasy, Pearly Ex: Talc Dull Ex: Graphite Silky Ex:

Malachite Earthy Ex: Hematite

Fill in the rest of your Mineral Brochure notes.

Use info already on the sheet

Use Ch 2 of your textbook (online @ home)