Question

this is mohs hardness scale.

mineral	hardness
gypsum	2
calcite	3
fluorite	4
apatite	5
orthoclase	6
quartz	7
topaz	8
corundum	9
diamond	10

which example lists minerals from hardest to softest?

• ∘ apatite, quartz, fluorite, talc
• ∘ diamond, talc, fluorite, topaz
• ∘ talc, calcite, orthoclase, diamond
• ∘ corundum, quartz, calcite, gypsum

Explanation:

Step1: Identify hardness values

From the table: corundum=9, quartz=7, calcite=3, gypsum=2

Step2: Verify descending order

Check values: $9 > 7 > 3 > 2$, which matches the sequence.

Step3: Eliminate incorrect options

• Option1: apatite(5), quartz(7) → order wrong
• Option2: diamond(10), talc(1) → order wrong
• Option3: talc(1), diamond(10) → order wrong

Answer:

corundum, quartz, calcite, gypsum