I got that amulet. You have to actually build two gems, you cannot have one pre-built and one you make yourself. At no time, not even in your inventory can you have more than two gems.
Hah, I was right. Anyone else have the 135 Tomb amulet? How long did that take? Hoestly I don't want to have to open up 7 tombs and die, and repeat like 10 times...
Honestly, the only reason I use a mouse recorder is to send all waves in endurance. Speaking of that, I just beat it with all hard settings, with all amulets (except 60 kill and 120 shrine kills, forgot to do that early on.) with two grade 30 gems.
here's a fun challange for premium players: start a new game, and see how many battles it takes to beat g13 (the first field) with full settings, not including shadow clash. this one took 13 battles. i bet it's possible to do in 8 or 9.
Here is a grade 12 WITH NO SPECIAL Prismatic, also. I get really bored, so I super gemmed a grade 2 filled with 1's. I did a full sheet of yellow, two of green until yellow dissappeared, and orange until lime disappeared. Orange never showed up at all, I have no idea why.
There is something wrong with two stats. The first is that the "Highest grade gem used in shrine" is one less than the actual value. The second is that one beacon destroyed with a gem bomb counts as two.