Question

An unknown mineral is scratched by a penny. It must _____

Answer 1

I think that it is softer than a diamond. As we all, a diamond is considered the hardest mineral and cannot be scratched by any kind penny.

Answer 2

This is about Mohs Scale of mineral hardness.

At a 2 it can be scratched by a penny.

Gypsum is a mineral at this hardness.

Based on this info, it is either a 2 or a 1 on the scale.

So likely Gypsum or Talc.