In HeartGold and SoulSilver you can buy Heart Scales,as prizes, they're available as Pokéthlon prizes but they're only available as Pokéthlon prizes on Wednesdays and Sundays.
catch a luvdisc, most of the time they will be holding a heart scale. fish for them. no, you can't buy a heart scale.
The heart scale is used as a payment for the move tutor, or you can sell them.
Catch a bunch of luvdisc they can hold heart scale.
You can find them underwater and if you catch a luvdisc they may be holding a heart scale.
to get a heart dive
in the underground
In Pokémon Crystal (GBC), there is no Heart Scale item. The Heart Scale item was introduced to the Pokémon video games in Generation III (3) (Ruby/Sapphire/Emerald). Thus, you cannot get the Heart Scale in Crystal. There is no Generation II-III trading, so there is no possible way to use the Heart Scale in Pokémon Crystal Version, sorry!
There's a man in Fallabur town who will re-teach a Pokemon a move for a heart scale. But you must find a heart scale, they are in several places on the map but are mostly in or near water.
move tutor house one heart scale - one move taught
you can buy a heart scale at the pokeathalon for like 200 pts. but only on certain days
you use it for the move maniac who reteaches your Pokemon a moves for one heart scale
Heart scales are found in cianwood? i never knew that! you can get heart scales in the pokeathlon too. also a guy in blackthorn will trade a heart scale to make Pokemon remember moves