Where does “Гәүһәр” come from?

Гәүһәр (Bashkir) comes from Persian گوهر, from Middle Persian gwhl, from Old Persian gauθra.

Ancestry of “Гәүһәр”, step by step

Step	Language	Word	Meaning
1	Persian	گوهر	jewel; gem; pearl
2	Middle Persian	gwhl	substance, essence, nature; jewel; stock, lineage
3	Old Persian	gauθra	—

Гәүһәр — Etymology, Origin & Word History | Etymology Explorer