There is an average of 84 Iron ore per chunk, 7.5 Gold, 3.4 Lapis, 3.1 Diamond.
Iron is very obviously the most common ore. Gold is about twice as common as Lapis and Diamond but cannot be fortuned. Fortune III will normally double the amount of Diamonds you collect but tripling them is not uncommon. Lapis is rather unique as without Fortune it produces 4-8 chunks but with Fortune III it can produce up to 80 chunks per ore which is almost 9 blocks.
So if you were to base it completely off of these facts the bank would look something like...
Iron: 1
Gold: 10
Diamond: 15
Lapis block: 8
But of course you must also consider that collecting diamonds is much more dangerous than any other ore and not everyone has Fortune III, so it's really down to opinion.
Iron is very obviously the most common ore. Gold is about twice as common as Lapis and Diamond but cannot be fortuned. Fortune III will normally double the amount of Diamonds you collect but tripling them is not uncommon. Lapis is rather unique as without Fortune it produces 4-8 chunks but with Fortune III it can produce up to 80 chunks per ore which is almost 9 blocks.
So if you were to base it completely off of these facts the bank would look something like...
Iron: 1
Gold: 10
Diamond: 15
Lapis block: 8
But of course you must also consider that collecting diamonds is much more dangerous than any other ore and not everyone has Fortune III, so it's really down to opinion.