Nobody has figured out how many there are but you could look it up in action replay and see if there is a cheat.
3
Moonstones are evolution stones for Normal-types. Use them on a Jigglypuff, or Clefairy. Other Pokemon use it too, but I can't think of them right now.
Yes You Can!
find them
in caves, people, pokemon, the syour.
There are 2 moonstones that are findable in LeafGreen. One is found in Mt. Moon, while the other is found in the Rocket hideout. Additional moon stones can be found on wild clefairy.
Im pretty sure you can.
try to catch a clefary! they usually have moonstones! ;)
there is only the sinnon region is Pokemon diamond
There is only one region in Pokemon diamond.
Ash has 6 Pokemon in Diamond version
493 are in diamond