Qenya
maril
noun. glass, crystal, crystal, glass
hyelle
noun. glass
Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
A noun glossed “glass, crystal” on the cover page of The Etymologies of the 1930s where it was the basis of a possible derivation of [ᴹQ.] Silmaril (EtyAC/SIL).
Conceptual Development: A similar word ᴱQ. marilla “pearl” appeared in the Qenya Lexicon and Poetic and Mythological Words of Eldarissa, again as the basis for [ᴱQ.] Silmaril (QL/59; PME/59).
Neo-Quenya: The word maril seems to be the best available Quenya word for “crystal”, and I would use it that way for purposes of Neo-Quenya.