Indeed Bismuth crystals are real, I grow them for a hobby using a method inspired by how silicon crystals are grown industrially. Those maps mentioned, Grim Plexus, Portico and of course Tourmaline (pronounce Toor-ma-leen) seem to me like a romantic reminder of the tabletop roots. Back then, when some dudes just grabbed some crystals from the parent's collection to make an interesting playing field.
BUT: those maps with the bismuth crystals are not realistic, and here's why:
First of all, the bismuth needs to be pure to grow crystals like that. Impure bismuth gets you small crystals that can't catch colour and crumble between your finger tips.
Second point, the colours. For the crystals to get those colours (so called temper colours, or heat tinting), it takes oxygen. The oxygen settles in the surface of the metal (or rather: half-metal) and creates those iridecent colours. The same thing happens when you heat iron until it glows, and when it cools down there are coloured stripes next to the part that was glowing. So those colours need an oxygen rich atmosphere, which is only generated by organisms that have sufficiently evolved to constantly generate oxygen.
Third point: bismuth crystals are very brittle. Even a Locust should turn those crystals to dust while stomping over them. Alright, in a game with shrubbery that stops Gaussballs and AC slugs unbreakable bismuth crystals are to be expected.
Alcom Isst, on 25 September 2017 - 11:12 AM, said:
I would love to grow some myself, make some awesome miniatures with them.
Bismuth has a density anomaly like water, which means it has less density in solid state than in liquid state. In other words, it expands when getting solid (and solid bismuth swims on liquid bismuth), therefore it's very difficult to remove it from a mold. But when you take a bismuth crystal and hold it into the undercooled molten bismuth (i.e. the liquid is cooler than the melting point), you can control the form the crystal will take. That way you can create very weird shapes, and it's a fascinating process.
Edited by Rick T Dangerous, 26 September 2017 - 08:35 AM.