1C (P) Moh's Hardness Scale

How do scientists test the hardness of a mineral?

• Comparing its mass to that of other minerals.

• Observing the luster of the mineral.

• Looking at the color of the mineral.

• Scratching the mineral against other minerals.

Refer to the Mohs Hardness Scale to the right. A mineral with a hardness of 7 can scratch –

• Apatite

• Topaz

• Corundum

• Diamond

A mineral with a hardness of 5 CANNOT be scratched by

• Gypsum

• Orthoclase Feldspar

• Diamond

• Corundum

Which mineral can scratch quartz, but is scratched by corundum?

• Topaz

• Talc

• Apatite

• Diamond

Which mineral is able to scratch corundum?

• Topaz

• Talc

• Apatite

• Diamond

Order the following minerals from hardest to softest.

• quartz

• calcite

• corundum

• fluorite

• talc

Organize these minerals into the right categories based on their hardness.

Groups:

(a) Greater than 2 but less than 6

,

(b) Equal to or less than 2

,

(c) More than 5 but less than 8

,

(d) 8 or Greater

• feldspar/orthoclase

• talc

• fluorite

• quartz

• corundum

• topaz

• calcite

• gypsum

• diamond

• apatite

Using this scale, which mineral can scratch fluorite?

• Talc 
• Gypsum 
• Apatite 
• Calcite 

Order the following minerals from softest to hardest.

• apatite

• topaz

• quartz

• diamond

• gypsum

Your unknown mineral is scratched by corundum, yet it scratches calcite. It is not apatite, but it is scratched by a 6. What is your unknown mineral?

• gypsum

• topaz

• fluorite

• apatite