Compounds,and mixtures that the natural forces of Mars have created.
Forces that are different than those on earth surface.On Mars C02
atmosphere that freezes into solid CO2 must have a great mixture of iron
sulfide in it,from those great dust storms.,and the iron sulfide from
volcanic ash. Here on earth our oceans separate mixtures by their
different bouyantcies. Mars does not have that feature. Mars has
the added feature to bring iron to its surface in greater
quantities(less gravity). To sum it up Mars sand is not the same as
earth's ,just like moon rock is not the same as earth rock.
Bert