Can Someone Tell Me , if all SETS are available in amethyst ? or what sets not support of amethyst . thank you!
All info on Crystals can be found there 
***Thanks For That Info Sir 
***
Super glad too help out
another question , i wish u know about this ^^ , how many % that the rare legend are found in what the codex said ?
for example: nadroji amulet found in past floor 200 from a powerful enemy . is their a chance that the legend nadroji amulet became an eternal rare legend ? in the same floor ? is it depends when i have eternalized ?
the chance too find rare legends at least too the extent of my knowledge is the exact same the thing that makes them rare it there drop condition which is from epic tier enemies and as for eternals, rare legends get the exact same chance as any other too be eternal they just drop less often hope that answers your questions 
**ahh oh thanks by the way . **
i cant reroll the frozen set T____T