I believe the last Erestrum gave about 800-1100 Ore. it takes about 15min to mine it, even with an epic Drill. EDIT: aprox. 1100 Ore. Still had the Erestrom of 3 small Deposits in my CC which is 360. Now I have a 999 Stack in the Cargo Box and produced 2 Large Truster...so a bit I reduced the stock.