krýstallos

krýstallos κρύσταλλος "krustig"

According to Beekes, the word is Pre-Greek — which Beekes claims is the case for all Greek words with the -αλλο- suffix.

Contrary to this, the apparent semantic and phonetic relationship to κρύος (krýos “cold; ice”), Latin crusta (“crust, bark”), and Old English hruse (“ground”) is striking - perhaps the word is a derivative of κρύος (krúos) with the addition of the Pre-Greek suffix.