I have spent to days and 8 hrs looking for diamonds in DS. Picked up at least 100 pieces of ore and yet not one diamond> Is this what i am spending my money on. For some reason i am not having fun. I have tried to be a good sport about this and suck it up. But enough already. Put some diamonds out there. Keep in mind you have 100,000 of thousands of people looking for the same thing.
You may not have picked up as many ore as you had thought. (You could have. I'm just saying you might not have.) If I were you, I would keep track of how many ores you pick up (not how many you get from a single ore pick--you can get three ore from a single pick), and if you get an diamond from it. Also, some have claimed (with convincing statistics to back them up) that if you only pick up one type of reagent and don't pick up anything else (like stone blocks, for instance, or wooden chests), your rate of rare drops will plummet.