Which area of the country, according to this map, is least rich in mineral deposits?

Either above Texas or in that area or below and around the mitt of Michigan.

They contributed many things, but here are some examples:

1) democracy - democracy as a political system was first implemented in ancient athens
2) some advances in mathematics - such as the pythagoras' law
3) the script - the roman script was adopted from ancient greek.

1)    "way light reflects from a mineral" —  luster ;

2)  "way a mineral breaks under stress " — cleavage ;

3)  "reveals true, natural color of a mineral
                (note: when in powdered form) — streak ;

4)  "least reliable property for identification" — color ;

5)    "measured using the mohs scale" —  hardness .