Pearlash

Pearlash is baked from potash at a kiln 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 at a glass furnace.

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.