1: orange transparent soap.
2: white translucent soap.
3: coffee. ( Ground )
4: black treacle.
This is how it will look . Mix only the soap and treacle together. You add the coffee in streaks to the final set, where it will be moving via a slight tilt or more, depending on how fast you want it.
You'll need a set like this. with a flat sheet of perspex for the rock sections to sit on. light the set from below with lamps. depending on how much glow you want, use any sort of yellow tungsten bulb. I like Halogen 500 watt bulbs, but that can get really hot for real. at a distance with those, you get a powerful light , and in a good spread, lower powered bulbs need to be closer and will create hot spots. So up to you.
Once lit from below. it will look like this. You can add post fire effects to make it more cinematic like in the mock up below.
Hope you have fun. There are other ways to do lava for movies. like the classic wall paper paste, but you should play around with it and see what you come up with.