Rock Identification Methods

Question 1

what is the Moh’s scale of hardness?

Answer 1

• a qualitative scale of how scratch resistant/hard a mineral is
• created by Frederich Mohs
• this scale is a chart of relative hardness of the various minerals.

Question 2

what does Moh’s scale start from and go up to?

Answer 2

starts at 1 with talc which is the softest mineral and goes up to diamond the hardest mineral at 10

Question 3

how can you test for carbonate rocks (sedimentary)?

Answer 3

HCl test - HCl is a strong acid and will fizz with carbonates

Question 4

how can you identify a rock by taking a thin section of it?

Answer 4

cut a thin section of rock until it is thin enough for light to pass through it, place it under a microscope, in ppl and xpl conditions, different minerals will behave in different ways as they refract light differently - birefringence

Question 5

how can you identify a rock just by looking at it?

Answer 5

you can identify certain elements relating to its colour, streak, grain size, roundness - angularity