Forum:Gem-Knight effects?

Someone told me I can use normal Gem cards like Gem-Armadillo for effects like Gem-Knight Prismaura. Prismaura says that I can only drop Gem-Knight cards to destroy a face-up monster. That's not true that I can use normal Gem cards, is it?

AnnoyingMacroPrick (talk • contribs) 15:39, May 16, 2012 (UTC)