peak, mountaintop, steep, lofty
崟 centers on a high, steep mountain peak: a lofty mountaintop that rises sharply.
崟 combines 山 (mountain) with 金, which likely contributes the sound. The exact historical development is uncertain, but the structure suggests a phono-semantic compound for a steep peak.
A mountain (山) with gold (金) at its top: imagine a steep, lofty peak where gold glitters at the summit.
For ギン, picture a steep mountain peak made of silver (銀, ぎん): the silver peak cues ギン.