In many places volcanoes exude a flow of liquid rock almost continously.
Today’s invention offers a way for local communities to exploit this, by offering mementos to visiting pyrophiles.
A mould could be created (by local craftsmen) and attached to a tractor using a long spar made of high melting point steel.
As the tractor drives the mould into the magma, the trapped gas escapes through a vent in the top.
The tractor withdraws and the rock within the mould gradually cools, allowing stone sculptures to be extracted for later sale.