Identifying Rocks and Minerals: Key Concepts and Properties

Bea, an Earth scientist, discovers a mix-up in her rock collection and explores how to identify minerals using their physical properties. The video covers the definition of minerals, their physical characteristics like color, luster, crystal form, streak, cleavage, fracture, and hardness. Bea demonstrates how these properties help distinguish between similar-looking minerals, ultimately identifying quartz, calcite, and selenite. The lesson concludes with a review and encourages viewers to practice identifying minerals.

What mistake did Bea make with her rock collection?

• She mixed up the names of the minerals.

• She mislabeled three minerals as the same.

• She broke one of her minerals.

• She lost some of her minerals.

What is a mineral?

• A naturally occurring gas with atoms organized in a pattern.

• A man-made solid with atoms organized in a pattern.

• A naturally occurring solid with atoms organized in a pattern.

• A naturally occurring liquid with atoms organized in a pattern.

Which of the following is NOT a physical characteristic used to identify minerals?

• Color

• Weight

• Crystal form

• Luster

What does the luster of a mineral describe?

• The color of the mineral

• The sheen or appearance of its surface

• The shape of its crystals

• The hardness of the mineral

What is a mineral's streak?

• The way it reflects light

• The shape of its crystals

• The way it breaks under pressure

• The color it has when ground into a powder

What is the difference between cleavage and fracture in minerals?

• Cleavage is the luster of the mineral, fracture is its streak.

• Cleavage is the color of the mineral, fracture is its hardness.

• Cleavage is when a mineral breaks along flat planes, fracture is random breaking.

• Cleavage is the shape of the crystals, fracture is the way it reflects light.

What tool do scientists use to measure the hardness of minerals?

• Mohs hardness scale

• Crystal form analyzer

• Cleavage tester

• Streak plate

Which mineral is identified by its ability to be scratched by a fingernail?

• Quartz

• Calcite

• Magnetite

• Selenite

What combination of characteristics is used to identify minerals?

• Luster and streak

• Color and weight

• Crystal form and hardness

• All physical characteristics together

Which mineral has a hexagonal crystal form and no cleavage?

• Hematite

• Calcite

• Selenite

• Quartz