According to Moh's hardness scale, your fingernail would be rated as 2.5. Juan and Carol are trying to identify an unknown mineral. Carol can scratch the mineral sample with her fingernail. Juan and Carol know the mineral MUST be one of these four choices. Based on the scratch test, the mineral is
I think the answer might be B. Calcite because it says it is at 2.5, it can't be gypsum because it's at 2 and when you round 2.5 it's closer to 3 than 2. So it will be B.
