Luster

Luster explained in an easy to understand way:

Imagine you're trying to choose the perfect lampshade for your living room, but every option seems to change the ambiance of the room differently. This situation is similar to how a mineral's surface reflects light, affecting the way we perceive its appearance. Just as the texture and material of the lampshade influence how light spreads across the room—creating either a cozy or stark atmosphere—the luster of a mineral determines how light interacts with its surface, giving it a unique shine or glow.