I tried to make some lava in Maya 2018 with Bifrost.
For the sim I used a high viscosity and made some variations in the density with a vertex map on the emitter and a simple wiggle expression.
I used a aiMixShader with two standard materials, one dark grey with some bump for the colder parts and one with some emission and a bit of transmission for the liquid lava. The emission color is driven by the density data with a ColorRemap.
For the mix, I made a mask using the density and velocity data plus various noises and a AO node.
Maya 2018, rendered with Arnold.
3,5M Bifrost voxels.