Luster refers to the way that minerals reflect light. A mineral with metallic luster looks like a metal when light reflects off it. Galena, for example, is composed of lead sulfide, and it has a metallic luster. Minerals with a nonmetallic luster, on the other hand, like orthoclase, may look glassy, greasy, waxy, brilliant, or dull and earthy. Color is the final physical property that we'll cover.
Color is color.
Now, a lot of minerals always appear to be the same color. Halite, for one, is always white. Lava, Magma, and Other Hot Stuff Magma is hot, melted rock that's below the Earth's surface. Really, it's just liquid Earth crust. Or just kind of ooooooozzzzes out of a crack in the crust.