Wait is this is like tic (Tinkers Construct) but more deadlier. I think tic is the best mod still, but however they have time to smelt. Anything death related, screw this I am out of here.
So this is what happened: My manual crucible setup uses a Dense Invar Burning Box and a Ceramic Crucible. I threw in 16 Blue Sapphires into the crucible, it filled up the crucible, then I turned on the burning box and it started heating up slowly. The temperature was approaching the melting point, around this time I turned my back for a few seconds to take a sip of my drink. Next thing I know, the crucible's empty and the thermometer's reading 2400 K. Oops.