Minecraft 21w14a
Now you can use fortune on iron, gold, and copper ore! A simple snapshot, but a massive game changer. See the changelog.
Fortune
Iron, gold, and copper ore loot tables use the same minecraft:ore_drops formula as all other ores. So, fortune 3 will drop 1-4 raw ore, 2.2 on average. See the wiki page on Fortune for the calculations, the numbers are the same as diamond.