Iridium crucible is actually easy to obtain!
- Find some amber and craft a pickaxe.
Its used for its silk touch properties so if theres no you can find use an enderpearl one… - Locate a sheldonite ore vein.
- Mine only full sheldonite blocks with your amber pickaxe. If i recall correctly only sheldonite gives an iridium as a sluice byproduct.
- Place 26 ores in a 3x3 blocks with strong dynamite in centre!
5)??? - PROFIT!