How do you get the moon stone in Pokemon HeartGold?

Answer 1

Well in order to get A stone there are over 12 ways like using the dowsing machine in areas like mountains but the easiest way I would have to say would be to wait until A Monday night and go to Mt Moon after 8 o'clock walk outside the mountain where the house is and go to the pond there will be lots of Cleafairy Dancing and when one sees you they all will run off and a moon stone will be left in ones place
There are two regions you can find it:

1. Kanto

2. Johto

You can also find it through the Pokéwalker

Please see the 'Related Links' section below for a detailed locations to find a Moon Stone. The items displayed are in alphabetical order. It's in the "Evolution Inducing Items" section, a little past the middle of the page.
One place is in Mt. Moon Square on Monday Nights every week, but there are several other areas.