We have QRTZ and DMND; these are monocrystaline (or just crystaline, if you prefer) solids. We have ICE, BRCK, ROCK, and various types of metals; these are polycrystaline solids. Finally, we have GLAS which is an amorphous solid; currently tpt's only amorphous solid as far as I know. But there's a fourth kind of solid which tpt does not yet have. Here my suggestion for it:
Quasicrystal (or QCRY):
QCRY is; obviously, a solid. To make it, mix molten QRTZ with molten GLAS and cool down the molten QCRY. Once cooled and solidified, QCRY can't be reheated back into LAVA. It combines the properties of QRTZ and GLAS, except that it's unbreakable. Like both elements, it's immune to ACID. Like QRTZ, it conducts electricity at -100C or at pressures of +8. It also bends photon lasers like GLAS and can be used as an unbreakable alternative material for prisms and fiber optic cables. QCRY; however, doesn't conduct heat but it's temperature can be adjusted by protons. QRCY; when at temperaures of 1000C or higher, makes photons into a particular color depending of temperature:
1000C= red
2000C=orange
4000C=yellow
8000C=white
9000C=blue
This somewhat simulates the fact that things emit light when hot enough. QRCY; like QRTZ, is a semiconductor and conducts to and from METL, PSCN, NSCN, and to but not from WIFI. Unlike QRTZ, it also conducts to and from INWR and can serve as an input for INST.
NOTE: The reason why I decided that molten QRTZ and molten GLAS should make molten QCRY is because in real life, the atomic structure of a quasicrystal is somewhere in between that of a monocrystaline solid and that of an amorphous solid and QRTZ is the only monocrystaline solid in tpt that melts while GLAS is the only amorphous solid in tpt of which I'm aware.
For those of you who already read this, I forgot to mention the fact that QCRY can't melt back into LAVA. I've added that part above; just after the part that explains the reaction that creates QCRY.