glass
瓈 centers on glass as a material. It is a rare character used specifically for glass or glass-like substances.
瓈 combines 王 (jewel, often used for glass-like materials) with 黎, which likely contributes the sound. The exact historical development is uncertain.
The left side 王 often appears in characters for precious or glass-like materials. The right side 黎 looks complex and shiny, like light reflecting off glass. Together they suggest glass.
For レイ, picture a ray of light passing through a glass pane: ray -> レイ, and the glass 瓈 lets the ray shine through.
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