Where does “रत्नदीप” come from?

रत्नदीप (Sanskrit) comes from Sanskrit दीप, from Proto-Indo-European dyew(p), from Proto-Indo-European dyew- — to be bright; sky, heaven.

रत्नदीप (Sanskrit): ‘jewels-lamp’; a lamp in which jewels give out...

Definitions

रत्नदीप traces back through two separate lines of ancestry.

Step	Language	Word	Meaning
1	Sanskrit	दीप	light; lamp, light source; light source
2	Proto-Indo-European	dyew(p)	to purify with light
3	Proto-Indo-European	dyew-	to be bright; sky, heaven

Step	Language	Word	Meaning
1	Sanskrit	रत्न	gift, present, goods, wealth, riches; jewel, gem,...
2	Sanskrit	राति	a favor, grace, gift, oblation; "the Giver";...