*EXTENDED RESPONSE Geologists use the Mohs scale to determine a
mineral's hardness. Using the scale, a mineral with a higher rating will
leave a scratch on a mineral with a lower rating. Geologists use scratch
tests to help identify an unknown mineral.
Mineral
Mohs
rating
Talc
1
Gypsum
2
Calcite
3
Fluorite
a. Use the table to write three if-then statements such as "If talc is
scratched against gypsum, then a scratch mark is left on the talc."
b. You must identify four minerals labeled A, B, C, and D. You know
that the minerals are the ones shown in the table. The results
of your scratch tests are shown below. What can you conclude?
Explain your reasoning.
Mineral A is scratched by Mineral B.
Mineral C is scratched by all three of the other minerals.
c. What additional test(s) can you use to identify all the minerals in
part (b)?