Period 6 element
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78.
Pokémon Platinum
The developers chose to call the game "Platinum" because of their observations that "diamond" has a "meaning of love", while pearl has a "meaning of happiness". They explained that they wanted to choose something that seems "beautiful", describing platinum as "different from a diamond, different from a gem, different from a pearl, different from something that nature creates, something [that] shines, something beautiful." They also created the story to be different from "Diamond" and "Pearl", commenting that they wanted to make Giratina seem "more fun, more interesting, cooler." They added Giratina's new area to make the story "more appealing". While "Diamond" and "Pearl" had gym leaders who sometimes had Pokémon not in keeping with the type they focus on, "Platinum" changes this so all Pokémon belonging to gym leaders were the appropriate type.