The properties of a mineral are determined by the "elements that compose it and the arrangement of its atoms".
Explanation:
Every mineral possesses its own unique "physical and chemical properties". To determine these properties, a small sample of the mineral is collected from a naturally occurring deposit of the mineral.
The size of this sample collected has nothing to do with the physical and chemical properties of the mineral.
The elements that form the mineral and the size of atoms of these minerals is what ultimately matters in the determination of the properties of the given mineral.