Mineral

if i said that mineral had “glassy” luster, but you looked at another sample of the same mineral and thought it had a “dull or earthy shine”, then how could that be? why isn’t luster a good property to identify minerals on its own?

Because the earth is not round ,but it may seem round when viewed from ,our planet but true some points earth is not round was an oblate spheroid -a square that it squashed as globe however is not even a perfect oblate spheroid.in fact isaac newton's first proposed that earth was not perfectly round but it was an oblate spheroid instead.that mean a square that is squashed as its poles and swollen at the