Then igneous rock wt to earth weight is:
.95 x 2.8 x 10^19 / 5.972 x 10^21 = .4454 x10^-2 = .4454% of the earth
Strontium is .034% of igneous weight
.00034 (.95 x 2.8 x 10^19) / 5.972 x 10^21 = .000904 x 10^19 / 5.972 x 10^21 =
.00015144 x 10^-2 = .00015144% of earth is srtontium
Igneous rock weight is in blue Strontium wt is in red.
Assumptions : You gave me correct numbers for earth wt and crust weight
%'s are by weight and are correct
I do not know if these are metric or US tons (suspect US tons)