Properties of MineralsIntegrated Science

7 PropertiesCrystal FormHardnessCleavage and FractureLusterColorSpecific GravityStreak

2 Properties We Will Not UseCrystal Form

◦Crystal ShapesCleavage and Fracture

◦Cleavage = breaks into pieces that are the same shape

◦Fracture = breaks into random shaped pieces

5 Properties We Will UseHardness

◦Mohs’ Scale is 1-10◦1 is very soft and 10 is very hard

Luster◦How the light is reflected off the mineral◦Types

Vitreous (Glass-Like) Metallic Dull Pearly Waxy

Vitreous (Glassy)

Metallic

Dull

Pearly

Waxy

5 Properties We Will UseColorSpecific Gravity

◦A value greater than 1 means it sinks in water. ( Will feel “heavy.”)

◦A value less than 1 means it floats in water.

Streak◦Color left by a mineral when streaked on

a porcelain plate.◦Not always the same color as the

mineral.

Dichotomous KeysA dichotomous key is a tool used

to classify or identify certain items.◦In the natural world they help to

determine names of trees, wildflowers, mammals, reptiles, rocks, and fish.

Dichotomous KeysKeys consist of a series of choices

that lead the user to the correct name of a given item.

"Dichotomous" means "divided into two parts".

Therefore, dichotomous keys always give two choices in each step.

Making A Simple Dichotomous MapThink about the important

characteristics that would define these animals!!!

Making A Simple Dichotomous Map

How would we make a Key for these organisms?

Notice we always are dividing these into two main characteristics!!!

Dichotomous Keys help identify things!!!

Can you figure out what these are?