good work!
edit, actually, wait a sec.
"The lava component is said to consist of "a solidified globule of mineral oil such as Ondina 17 (R.T.M.) with a light paraffin, carbon tetrachloride, a dye and paraffin wax."
The clear liquid is roughly 70/30% (by volume) water and a liquid which will raise the coefficient of cubic thermal expansion and encourage the movement. The patent recommends slip agents such as propylene glycol for this. However, glycerol, ethylene glycol, and polyethylene glycol (PEG) are also mentioned as being sufficient.
"
"The liquid in which the globule is suspended is usually dyed water"
so it's not always mineral oil. there might still be hope for water!!!