Haar-Tok (translated roughly as sacred/holy rock) are former TzHaar who have cooled and solidified into rock form. Haar-Tok can be found scattered throughout Mor Ul Rek.
While speaking to TzHaar-Mej-Bal or TzHaar-Mej-Dir, they reveal that Haar-Tok are in essence, dead, as they cannot move or communicate, but the former TzHaar remains conscious inside the solidified rock.
According to TzHaar-Hur-Lek in the 17th Postbag from the Hedge letter, TokKul are made out of the corpses of the TzHaar. It can be assumed then that the Haar-Tok in the city are eventually taken away and made into TokKul.