Answer:
Color-Color in minerals is caused by the absorption, or lack of absorption, of various wavelengths of light. The color of light is determined by its wavelength. ... Some elements have electrons that absorb certain wavelengths or colors.
Streak-The streak of a mineral is the color of the powder produced when it is dragged across an un-weathered surface. ... Small amounts of an impurity that strongly absorbs a particular wavelength can radically change the wavelengths of light that are reflected by the specimen, and thus change the apparent color.
Hardness-The hardness of minerals is diagnostic because the hardness is determined by the strength of bonds and the structure of the mineral lattice. Hardness is basically the stress required to create and grow extended lattice defects such as micro-fractures, stress twins, and dislocations.
Cleavage-The tendency of a mineral to break along flat planar surfaces as determined by the structure of its crystal lattice. These two-dimensional surfaces are known as cleavage planes and are caused by the alignment of weaker bonds between atoms in the crystal lattice.