Mineral Hardness and Identification

The video tutorial explains the concept of hardness using the Mohs hardness scale, which ranges from 1 (talc) to 10 (diamond). It describes tools like fingernails, copper pennies, and glass used to test mineral hardness. The instructor demonstrates testing various minerals, comparing their hardness, and identifying them based on their ability to scratch or be scratched by these tools. The video concludes with a discussion on diamond, the hardest known material.

What is the hardest mineral on the Mohs hardness scale?

• Calcite

• Diamond

• Quartz

• Talc

Which mineral is known to be the softest on the Mohs scale?

• Calcite

• Talc

• Gypsum

• Fluorite

Which tool is NOT commonly used to test mineral hardness?

• Streak plate

• Plastic spoon

• Copper penny

• Fingernail

What is the approximate hardness of a streak plate?

• 4

• 6.5 to 7

• 8

• 5

If a mineral can be scratched by a fingernail, what is its approximate hardness?

• 7

• 5

• 2.5

• 1

Which mineral is known to be softer than a fingernail?

• Quartz

• Apatite

• Gypsum

• Fluorite

Which mineral is identified as being harder than a copper penny but softer than a steel nail?

• Calcite

• Talc

• Gypsum

• Quartz

What is the hardness of olivine on the Mohs scale?

• 5

• 8

• 6

• 7

Which mineral is used to demonstrate a hardness of about 5?

• Apatite

• Calcite

• Talc

• Diamond

What is the natural crystal form of diamond?

• Orthorhombic

• Hexagonal

• Tetragonal

• Cubic