I'm getting kind of broke in Animal Crossing: New Leaf, so I've started to look for money rocks. How many money rocks are there in total?
Occasionally you will find a rock filled with ore that works the same as a money rock - each time hit, a piece of ore comes out. That happens instead of a money rock. Had it happen to me today. There was still a rock that broke and had 1 piece of ore inside in the town. Also you can get up to I think 16,000 bells from one money rock if you're quick enough. I'd recommend island fishing and beetle hunting after 4PM though, if you're broke. Sharks galore!
There is one money rock per day, and one ore rock per day.
One of your existing rocks turn into a money rock each day aswell as a new rock which will break when you hit it with a shovel and drops an ore. When you use a silver shovel on a money rock, there is a chance the money turns into ores.