jade
瓘 centers on jade as a precious stone, often used in ceremonial or ornamental contexts.
瓘 combines 王 (jade) with 雚, which likely contributes the sound. The character is used for a type of jade or jade-like stone.
The left side 王 is the jade radical, and the right side 雚 looks like a heron or a complex ornament. Picture a heron-shaped jade carving: 瓘 is jade.
For カン, imagine a can made of jade: can -> カン, and the jade can is a precious container.