As the above link says, "during this test, buying one of the 10-chest bundles guarantees a gemstone in addition to the gemstones you can find in the chests themselves." I bought five 10-chest bundles so far, and I only get 3 gemstones from them ( it supposed to be 5, right?). So, is there anyone could explain what happened to the "guaranteed gemstone"?
Sounds like it may have been reserved for the PBE. Or maybe the promo chest bundles aren't the chest bundles currently available in the store. Either way, an actual Riot answer would be helpful here.
That was part of the PBE, there will be guaranteed gem bundles in the future though for certain promotions and such.
There is no guarantee. The guarantee was on the PBE for the purpose of testing gemstones, as far as I know. Gemstones are supposed to be roughly 1 in 30, so you're actually quite lucky to have gotten 3 in 50 chests.
Perhaps there will be this kind of promotion in the future. I think I remember reading that the PBE gem special was not guaranteed to go to live and was predominantly to chest gemstones (it was also mentioned that gemstones on the PBE gave a chest+key, but they may do something else on live - eventually they added hex tech annie but kept the chest+key).
