Answer:
COLOR of a mineral/rock
Step-by-step explanation:
Luster is defined as the property of a mineral that describes how light is reflected from the mineral's surface (including rocks as well as crystals). For example, pyrite shows metallic type of luster.
Streak is the color that is produced when a mineral is rubbed on a streak plate. These are finely powdered form. For example, hematite appears to be in different colors such as blackish, brownish or reddish, but all of them produces a reddish colored streak.
These two properties of minerals are directly related to the color of a mineral. Color is one of the primary property of identifying a mineral or rock.