Pagarsi
Yes my friend and the following will help to better understand the logistics.
Pure hematite is 69.9% Fe for a specific gravity (sg) of 3.64 (3.64 tons per cubic metre).
If you were to fill a 1 cubic metre container with nothing else but 100% hematite, it would weigh 5.2 net tons.
Thus, 58% of 5.2 = 3.02 sg