Diamonds will burn so that's technically not the worst enemy to face.
What?
I can't picture this. Its like division by 0 for my brain...
Diamonds in real-life and DF are flammable. They aren't oxidized like many other gemstones. They are made of coal, which is flammable.
Thus, irrespective of its allotropic form, carbon remains solid at higher temperatures than the highest melting point metals such as tungsten or rhenium. Although thermodynamically prone to oxidation, carbon resists oxidation more effectively than elements such as iron and copper that are weaker reducing agents at room temperature.
diamonds are actually the best currently known thermal conductor. there are projects to use synthetic diamonds as heatsinks for computers.
it takes approximately 700 celsius to oxidize diamond at normal pressure. high pressure allows it to push 2,500 celsius. blast furnaces for iron (hematite and magnetite ores) require approximately 2000 celsius.
so yeah, put your diamond blob in one of your magma smelters or something. the low range for magma is about 700 celsius.
though, huh
that's odd
high range is around 1300 celsius which shouldn't actually melt iron. the highest speculated magma temps were komatiite flows at about 1600 celsius and that was 2.5 billion years ago during the archaean.
so either the world is extremely hot, extremely young, or armok is hanging out down there