Where does “زُمُرُّد” come from?

زُمُرُّد (Arabic) comes from Ancient Greek σμάραγδος, from Proto-Semitic bariq- — lightning.

Ancestry of “زُمُرُّد”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	σμάραγδος	emerald
2	Proto-Semitic	bariq-	lightning