Miss Em couldn’t wait to start this Gizmo. She had so much fun that she insisted on identifying all 26 samples. Later that day she went back and did some again on her own.
Minerals are identified using 5 characteristics: appearance (colour, shape, and lustre), density (mass divided by volume), hardness, streak test, and acid reaction.
She soon discovered that density and hardness were the most reliable indicators. She would search the answer table for minerals with the same numbers as those she measured. Then she would look at acid and streak tests (because most of the sample failed both tests it was rarely useful to start with these results). She found that appearance was the most variable: she would think it was pearly when it was metallic, for example. This led to a discussion about the difference between objective and subjective measurements.