Answer:
When the surface of a mineral reflects light in manner that is similar to a metal, the mineral is said to have a metallic luster.
Step-by-step explanation:
A mineral is a pure, naturally occurring, solid chemical substance. They have a crystalline structure and a definite chemical composition.
Another physical property that can be used to define a mineral is luster. It can be of two types: metallic luster and non-metallic luster.
A mineral is said to have a metallic luster, if it has high reflectivity like a metal. Examples : pyrite, galena.