[@pyroman]I don't think he would, unless You-Know-Who told him about them (I don't want to spoil anything for those who haven't seen the latest episode). 
I definitely think that Stanley would try to use them as new attractions for the Mystery Shack. XD
I'm also thinking that Dipper and Mabel would find a warp pad in the forest and the gems (and Steven) would appear there in front of them. XD

[@Akayaofthemoon]Hi Akaya