beautiful jade
珺 centers on a type of beautiful jade, a precious stone valued for its beauty.
珺 combines 王 (jade) with 君, which likely contributes the sound クン. The character is a phono-semantic compound for a type of beautiful jade.
The left side 王 (jade) tells you it's a precious stone, and the right side 君 (lord/ruler) suggests it's a jade fit for a ruler—beautiful jade.
For クン, imagine a beautiful jade crown (クン sounds like 'coon' in 'raccoon', but closer to 'coon' as in a shortened 'crown'): a lord's crown made of beautiful jade. Crown -> クン.