1.2 billion tonnes of coal, page-17

The way I see it is that an inferred resource of 1Bt would yield 750Mt of JORC resource for HDG. The grades are average, so it would probably be worth about 6-7 cents per tonne in EV. You would be looking at a market cap of about $50M-$55M if the resource of that size was JORC defined and HDG exercised the option for 75% ownership. Currently the market cap is about $15M, so it's definately worth a punt in my opinion.