Minerals2-1

Wednesday May 15, 2013 Objective: Identify minerals and their

properties.

Homework: Mineral lab Due Friday

Bell work: • Are water and ice minerals?

• Can minerals be found in rocks?

• Can minerals exist as gas, liquid, and solid?

Minerals have four characteristics A mineral is a

substance that: • Forms in nature• Is a solid• Has a definite chemical

make up It consists of specific combinations of elements

• Has a crystal structure Atoms are arranged in an orderly, repeating, 3-D pattern.

chlorine

sodium

Questions to Ponder Are water and ice minerals?

• Water: No, it is not a solid

• Ice: Yes, it fits all four categories

Can minerals be found in rocks?• yes

Can minerals exist as gas, liquid, and solid? • No, it has to be a solid

Rock vs. Mineral Are all rocks minerals?

• No• A mineral has to have all four

characteristics • A rock only needs two

It forms naturally and it is solid• A rock usually contains two or more types of

minerals

Crystal shapes: A repeating 3-D pattern

Cubic Tetragonal Hexagonal

Orthorhombic Monoclinic Triclinic

Identifying a Mineral Color and streak Luster Cleavage Fracture Density Hardness

Color and Streak The same mineral

can be many different colors, but the streak color is generally the same.

Streak: • The color of a mineral

powder left behind when a mineral is scraped across a surface.

Luster Luster describes the way in which

light reflects from its surface. metallic or nonmetallic.

Cleavage The tendency to break along flat

surfaces.

Fracture The tendency of a mineral to break

into irregular pieces.

Density The amount of mass in a given

volume.

Hardness The resistance of a mineral to being

scratched.