Which property is most useful in mineral identification?hardness colorsizetexture

The most useful property in mineral identification is hardness. This is because the hardness of a mineral is a specific and consistent property that can be tested easily. It is determined by the resistance which a smooth surface offers to abrasion. The degree of hardness is determined by observing the comparative ease or difficulty which which one mineral is scratched by another.

Color can be misleading as a single mineral can occur in many different colors. Size is not a reliable identification method as the size of mineral specimens can vary. Texture can provide some clues, but it is not as reliable as hardness.

So, hardness is the most useful property in mineral identification.