Warm-Up: List the 5 characteristics of a mineral

Warm-Up:

• List the 5 characteristics of a mineral.

Topic Objectives

• Identify the 5 properties of a mineral.

• Identify a mineral using its properties.

• Describe why color is not a good way to identify a mineral.

Mineral Properties

What are mineral properties?

• They are characteristics about specific types of minerals…ex. hematite is red and sulfur is yellow

Why should we care about mineral properties?

• Many minerals look the same, so if a scientist needs to identify a mineral, they must test its properties to figure out which type of mineral it is.

What are the 5 properties we will study?

1. Color

2. Luster

3. Streak

4. Hardness

5. Crystal Structure

Property #1: Color

• You can determine the color of a mineral by looking at it (Duh!), but make sure you are specific!

What color are the minerals below (specifically)?

Why is knowing the color not enough information to identify the mineral?

• Problem #1- Many different types of minerals have the same color…(milky quartz and calcite)

• Problem #2- One type of mineral can come in many different colors… (ex. quartz)

Property #2: Luster

• The luster of a mineral is the way that the mineral shines in light.

• Metallic Luster: Shines like polished metal

• Nonmetallic Luster: Does not shine like polished metal (can look glassy, earthy, oily, dull, etc.)

Property #3- Streak• The streak of a

mineral is the color of a mineral’s powder.

• This is determined using streak plates that gently scratch the mineral to turn some of it to powder.

Property #4- Hardness

• The hardness of a mineral is its resistance to being scratched.

1. Which mineral can scratch topaz, but not diamond?

2. Which mineral can only scratch talc?

3. Which mineral can scratch diamond?

Property #5- Crystal Structure

• The atoms in minerals are arranged into orderly structures (specific shapes).

- Cubic- Tetragonal- Orthrohombic- Hexagonal

Cubic

• Three axes (x, y, z) of equal length.

Tetragonal

• Three axes (x, y, z), with two of equal length and one of different length.

Orthrohombic

• Three axes (x, y, z), all of different length.

Hexagonal

• Three axes of equal length, one of different length (4 axes total!=6-sided).

Exit Question:

• Answer “Connecting Concepts” question only from pg 55 of text.

Use the key on pgs. 54-55 to answer.