>>36180747Palkia is based on pearls, which originate in oysters, sea creatures. Water-type.
Dialga is based on diamonds, which are among the hardest known substances on the planet. Steel is the hardest material in Pokemon and the strongest defensive type.
Giratina is Ghost-type not because of its connections to platinum, but because it lives in a dimension opposite to ours. We are unable to perceive its existence just as Giratina cannot perceive ours. One of us must cross over to the other side for us to interact. This is similar to how Normal- and Ghost-types interact; they cannot hurt the other. If we're in the "normal" (regular) world, it makes sense for the Distortion World to be the "ghost" (reverse) world.
