red jewel, beautiful jewel
瓊 centers on a precious, beautiful red gem or jewel. It refers to an ornamental treasure, often with a reddish hue.
瓊 combines 王 (jade/gem) with 敻, which likely contributes the sound and possibly a sense of distance or rarity, but the exact historical development is uncertain.
The left side is the gem radical 王, and the right side 敻 looks like an eye 目 peering through a distant opening 冂 with a walking stick 夂, as if searching for a rare red jewel.
For ケイ, imagine a beautiful red jewel shaped like the letter K: K -> ケイ, and it gleams like a precious gem.