All right.  The tech behind a spectroscope seems relatively simple.  Next on the plan is building a spectroscope, seeing how it plays with Prestidigitated and natural materials as they get burned within a flame of standardized temperature - they should see about getting a 'bound fire elemental' for that possibly, it seems like the sort of heat output that might be possibly more standardized than burning wood or candles - and then seeing if Keltham can Prestidigitate calcium ash or a different metal into burning the color that element-23 should burn, and that'll give them a reference point for looking through fake spellsilvers.

Is there any sort of magic for magnifying things enormously, like Keltham might use to zoom in on a less than 0.1% divergence in the thermal expansion of two different metals?

All right.  The tech behind a spectroscope seems relatively simple.  Next on the plan is building a spectroscope, seeing how it plays with Prestidigitated and natural materials as they get burned within a flame of standardized temperature - they should see about getting a 'bound fire elemental' for that possibly, it seems like the sort of heat output that might be possibly more standardized than burning wood or candles - and then seeing if Keltham can Prestidigitate calcium ash or a different metal into burning the color spectrum that element-23 should burn, given its orbitals, and that'll give them a reference point for looking through fake spellsilvers.

Is there any sort of magic for magnifying things enormously, like Keltham might use to zoom in on a less than 0.1% divergence in the thermal expansion of two different metals?