VIDEO : 'Pokemon Go' Makes Sinnoh Stone Harder to Find

Pokemon Go's newest evolutionary item is now a lot more elusive. Earlier this month, Pokemon Go added the Sinnoh Stone to the game to let players evolve certain Pokemon species into new forms first seen in Pokemon Diamond and Pearl. The Sinnoh Stone granted access to powerful Pokemon like Rhyperior, Electivire, or Roserade, but could only be obtained as a Research Breakthrough reward. Thousands of players have reported not getting the Sinnoh Stone in their weekly Research Breakthrough rewards, which means it's now significantly harder to obtain the item and evolve some new Pokemon.