Which is the least reliable method for identifying a mineral?
a. color
b. streak
c. luster
d. cleavage

A. color

A mineral can be defined as an inorganic compound that is obtained by digging up the earth crust. It is available in the ore deposits. The physical characteristics and chemical composition of the mineral can be used for the identification of the mineral.

Color, streak, luster and cleavage are physical characteristics of the mineral which can be useful for identification. Streak is a test in which the mineral is scratched to identify it's internal color for identification, luster means how a mineral shows reflection against the light, cleavage is the breaking of the mineral into parts, it tells the internal composition of the mineral.

Color is the least reliable method for identifying a mineral because two or more minerals can have the same color.  

bacteria could be both, harmful and to us. harmful bacteria could make us sick and probably even by getting the chances of getting a disease, but good bacteria fight it off with your immune system. there is always bacteria everywhere we go. we need to make sure to wash our hands after using the restroom, before eating, after eating, after petting an animal too. so you see, bacteria is everywhere and is harmful or . i hope this . : ) : ) : )