Knowing that platinum will break down and oxidize before it actually melts, I am seeking to find a reliable resource that would tell me the useful temperature range for platinum.
ASM Handbook Volume 2 Properties and Selection: Nonferrous Alloys and Special-Purpose Materials:
"Platinum has exceptional resistance to oxidation. Upon heating in air at all temperatures to the melting point, it remains untarnished. At temperatures above about 750 °C, slight weight loss occurs due to volatilization of the metal itself and the formation of a volatile oxide of platinum. This oxide is essentially PtO2, although the presence of both PtO2 and PtO has been noted; mass spectrometric techniques indicate that the main oxide molecules are PtO2 and PtO3. As higher temperatures are reached, loss to volatilization of the oxide species becomes greater than that of the metal."
This is just a start. You can see a graph of mass loss in this Handbook, available here: