How Mineral Hardness Determines Scratchability

What mineral is able to scratch glass?

a. Quartz

What mineral is unable to scratch a copper penny?

b. Calcite

What minerals are able to scratch calcite?

c. Quartz and Pyrite

What mineral is able to scratch pyrite?

d. Quartz

Answer

a. Quartz can scratch glass.
b. Calcite cannot scratch a copper penny.
c. Both quartz and pyrite can scratch calcite.

Mineral hardness plays a crucial role in determining the scratchability of different minerals. The Mohs hardness scale, which ranges from 1 (softest) to 10 (hardest), is commonly used to measure the hardness of minerals.

Quartz, with a hardness of 7 on the Mohs scale, is able to scratch glass because it is harder than glass, which has a hardness of 5-6. This means that quartz can leave a visible scratch mark on glass.

On the other hand, calcite, with a hardness of 3 on the Mohs scale, is unable to scratch a copper penny. A copper penny has a hardness of 3.5-4, making it slightly harder than calcite. Therefore, calcite will not be able to scratch a copper penny.

Both quartz and pyrite have a hardness greater than calcite, which is why they are able to scratch calcite. Pyrite, with a hardness of 6-6.5, can easily scratch calcite, which has a hardness of 3.

Understanding mineral hardness is essential in various fields such as geology, mineralogy, and material science. It allows scientists to identify and differentiate minerals based on their physical properties, including scratchability.