Mining Fortune

is a stat that is identical to the and  stats. It increases your chance to get multiple drops from mining ores (It doesn't affect the amount of Cobblestone and other blocks not considered an Ore), and can be increased with your level and HotM upgrades. It functions similar to, in that every 1 of it you get it adds an extra 1% chance to get double drops. Anything above 100 gives a chance for triple drops, anything above 200 gives a chance for quadruple drops, etc.