Gold (element), character used in personal name
鋆 centers on gold as a precious metal, used here primarily as a personal name character. Its standalone meaning is tied to the element gold.
鋆 combines 金 (metal, gold) with 均, which likely contributes the sound. The exact historical development is uncertain, but it is a phono-semantic compound related to gold.
The bottom is 金 (gold), and the top 均 suggests evenness or uniformity. Imagine a perfectly uniform gold ingot used to stamp a personal name seal.
For イン, picture an innkeeper stamping a guest's name in gold ink: inn -> イン, and the gold character marks the register.