Sorry to burst your bubble, but no, they are not.
From what there is, type gems were only available in Gen 5 (Black, White, Black White2).
In an event, they may appear on a Pokémon, but thats the only way you can get them.
Edit: You may be able to get the gems, I Rock Smashed a rock and received a Normal Gem. I'm not sure if thats the only one, but thats what I think it is.