Pearlash is baked from potash at a kiln (uses 1 fuel) or magma kiln by a dwarf with the furnace operator labor enabled. Its primary use is in the manufacture of clear glass and crystal glass items. Pearlash in real life
Pearlash comes in bars, stored in a bar stockpile and viewable in the stocks screen under "bars". Since it is a bar it can also be used to make constructions and workshops.
[MATERIAL:PEARLASH] - reconstructed from data extracted from memory