Clefairy and the Moon Stone

S1 E6: At Mount Moon, our friends rescue a scientist named Seymour from a bunch of Zubat, and Brock manages to catch one before the battle is over. A grateful Seymour then leads Ash and his friends deep into Mount Moon to find the storied Moon Stone, which is said to increase the power of Pokémon!Further into the tunnels, Ash spots a Clefairy carrying a Moon Stone. He considers trying to catch it, but Seymour tells him Clefairy prefer to live at Mount Moon. Ash decides to leave the Clefairy in peace, but the Team Rocket trio show up with some catching plans of their own!Will Team Rocket steal the Moon Stone? Are there other Clefairy lurking about, and do they carry Moon Stones, too? And is the legend of the Moon Stone true?