Janeko's Fiery Crucible: This device is an adamantine folding forge powered by magic. When folded, it fills approximately half a cubic foot, and when unfolded, opens in to a two-foot cube with one open side, and shutters that can be drawn to decrease the size of the aperture on the open side to as small as three inches squared. A prepared spell with the [Fire] descriptor can be cast 'into' the crucible, such that it is used to power the forge instead of having the normal effect. The forge, when thus charged is magically held at a high temperature for one minute per caster level, and then cools normally – thus, it is most efficiently used when kept well insulated, so that the burning heat within can be contained longer than otherwise. The heat reached inside the box varies by the level of the spell cast in to it, like so:
Cantrip: 300 to 400 degrees Fahrenheit – a normal kitchen oven.
1st level: 400 to 800 degrees Fahrenheit – hot enough to temper steel.
2nd: 800 to 1200 degrees Fahrenheit – Metal glows red-hot.
3rd: 1200 to 1800 degrees Fahrenheit – Metal glows orange. You can forge and harden iron.
4th: 1800 to 2600 degrees Fahrenheit – Metal glows white-hot. You can forge and harden steel.
5th: 2600 to 3200 degrees Fahrenheit – Iron melts. You can temper mithril.
6th: 3200 to 4000 degrees Fahrenheit – You can forge and harden mithril.
7th: 4000 to 4800 degrees Fahrenheit – Mithril melts. You can temper adamantine.
8th: 4800 to 5600 degrees Fahrenheit – You can forge and harden adamantine.
9th: 5600 to 6400 degrees Fahrenheit – Melt adamantine (destroying the crucible in the process) (5600 to 6400 Fahrenheit.)
(Note: For Adamantine, I used the melting point of Tungsten.)
(Clearly unfinished – I'll get back to this shortly.)