Question

Identify the minerals based the decreasing order of Moh's Scale of Hardness

• A. Topaz $\gt $ Quartz $\gt $ Orthoclase $\gt $ Fluorite
• B. Quartz $\gt $ Fluorite $\gt $ Topaz $\gt $ Orthoclase
• C. Fluorite $\gt $ Quartz $\gt $ Orthoclase $\gt $ Topaz
• D. Topaz $\gt $ Orthoclase $\gt $ Fluorite $\gt $ Quartz

Hint:

It is very helpful to memorize the 10 minerals of the Mohs scale for geology questions.
A common mnemonic is: "Tall Girls Can Fight And Often Quit, They Cry Diamonds."
1. Talc 2. Gypsum 3. Calcite 4. Fluorite 5. Apatite 6. Orthoclase 7. Quartz 8. Topaz 9. Corundum 10. Diamond

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
We need to arrange the given four minerals in order from hardest to softest, according to the Mohs scale of mineral hardness.

Step 2: Detailed Explanation:
The Mohs scale is a qualitative ordinal scale that characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material.
Let's recall the hardness values for the minerals listed:
-

Topaz: Hardness =

8 -

Quartz: Hardness =

7 -

Orthoclase (a type of feldspar): Hardness =

6 -

Fluorite: Hardness =

4
Arranging these in decreasing order of hardness (from hardest to softest) gives:
Topaz (8) $\gt $ Quartz (7) $\gt $ Orthoclase (6) $\gt $ Fluorite (4)

Step 3: Final Answer:
The correct decreasing order of hardness is Topaz $\gt $ Quartz $\gt $ Orthoclase $\gt $ Fluorite.
This corresponds to option (A).