February 10, 2015 Goal: Identify the properties of minerals Pick up paper Open to Minerals Notes and homework (back) Write HW: Do Quiz Review Quiz Thursday: Weathering, Erosion, Minerals Extra Credit Black Scientist posters due Friday DO NOW: Using notes and reading you picked up, Complete the back!

1. Two Most Common Elements in Earth’s Crust?

1a. Water makes up ¾ of earth surface 1a. Water makes up ¾ of earth surface. So Hydrogen isn’t as common in Crust, it’s in oceans!!

What is a Mineral? Minerals make up rocks 2. A mineral is a naturally occurring, inorganic, solid, that has a crystal structure & a definite chemical composition. Example: Quartz What is a mineral? Naturally-occurring = Never man-made Ex: Like rocks

Inorganic = 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.

Set Chemical Composition Quartz: Chemical Formula SiO2 What elements? How many atoms?

Color 2a. Color can’t be used alone to find the identity of the mineral. Because Some minerals come in many colors. Reliable only with metallic minerals. They have a distinctive color when tarnished. Ex. Bromide tarnishes to an iridescent color.

Cleavage One way minerals break Easily split along flat surfaces Ex: Mica & Halite

Fracture Another way minerals break Break unevenly in irregular ways Chipped Shell-like Ex: Quartz Jagged points Ex: Copper & Iron Crumbles Ex: Clay

Lead Quartz

Mohs Hardness Scale Hardness can be tested by a Scratch Test 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 softer mineral Mineral can be scratched by any harder mineral Minerals that have the SAME hardness can scratch each other.

3. Which marterial is harder, calcite or copper penny? Penny has hardness of 3.3 COPPER PENNY! 3a. Hardest mineral: Diamond Softest Mineral: Talc

Luster Luster describes how light is reflected from the mineral’s surface. What the mineral looks like.

Types of Luster Metallic Ex: Galena Glassy Ex: Topaz Waxy, Greasy, Pearly Ex: Talc Dull Ex: Graphite Silky Ex: Malachite Earthy Ex: Hematite

Streak Test 4. The color of the mineral’s powder in a powder form is called: STREAK. That’s what is left behind when it is rubbed across a rough surface Example: Pyrite (aka “fool’s gold”) looks like gold, but its streak looks greenish-black

Solid Atoms are arranged in a definite pattern. This repeating pattern is called a crystal. Not a liquid or a gas!

5. How do CRYSTAL STRUCTURES grow?

5. CRYSTAL STRUCTURES grow as atoms are added to its surfaces, edges or corners.

Chemical properties Chemical properties refer to how the mineral reacts with an acid. Example: Calcite (CaCO3), the main mineral in limestone and marble, bubbles when hydrochloric acid is placed on it. CaCO3 and HCl

6. Melted Rock Material in the Earth Is called MAGMA 6a. It forms minerals as it cools and atoms arrange into orderly structures.

7. Tetra means four and hedron means side, so tetrahedron means: FOUR SIDES. 7a. The elements that are bonded together to create silicates are oxygen and silicon.

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After You Read: What is similar and different about cleavage and fracture?

Cleavage One way minerals break Easily split along flat surfaces Ex: Mica & Halite

Fracture another way minerals break Break unevenly in irregular ways Chipped Shell-like Ex: Quartz Jagged points Ex: Copper & Iron Crumbles Ex: Clay

What are the Physical Properties of Minerals? Physical Properties include “tests” you can perform on minerals to determine what type of mineral they might be. These include:

Physical Properties Identify Minerals Crystal Structure Color Cleavage Luster Streak Fracture Hardness

What is a Mineral? Minerals make up rocks A mineral is a naturally occurring, inorganic solid that has a crystal structure & a definite chemical composition. Example: Quartz What is a mineral? Naturally-occurring = Never man-made Ex: Like rocks

Lab #9: Mineral Identification Read introduction. Fill in heading, answer Problem. Problem: What methods can you use to identify minerals?

Identifying Minerals Using Color and Luster Read background information in group. Answer questions 1-5. One person bring WS to Mrs. Procario to check. Pick up mineral samples. Be careful with them! 5. Write # of sample (see mineral) and identify color and luster. One person hand in worksheet for your group. (make sure all names are on it) 7. Return mineral samples.

3. Density It’s a calculation (math problem!) Use a balance to find the mass Place the mineral in H2O to find the amount of water it displaces. This amount is the volume of the mineral. To find the density, divide mass by volume Ex: Sample of Olivine Mass = 237 g Volume = 72 cm3 Density = 237 g/ 72 cm3 = 3.3 g/cm3

Science Standard S6E5. 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