míriel

adjective. sparkling like jewels, like a jewel

An adjective meaning for “sparkling like jewels” (RGEO/64) in the poem A Elbereth Gilthoniel (LotR/238). It was the passive participle of the verb míria- “to sparkle like jewels” (PE17/24). Tolkien also considered connecting it to Quenya past passive participles like káriela in notes from 1969, perhaps from a verb ✱mir- with a Q. past participle míriela, but this Q. form was deleted and the whole thing seems to have been a transient idea (PE22/152).

Note: One of the forms from PE22 was published as mirieail, but Christopher Gilson confirmed in a Discord chat that the actual form was miriail: discord.com.