Use beeswax honey comb sheet to mould a simplified human face mask and border.
Use that to make a plaster mould.
Kiln dry mould.
Test mould with clear bullseye.
I think that a double thickness of glass would be good so...fuse two layers then slump.
Cut slits or spaces at mouth and eyes.
Use black beads on thread or wire that coil at the back that spill out of the gaps.
Fasten to the wall ???