Qenya
alka
noun. ray of light, ray of light, [ᴱQ.] light of day; shining
mirilya-
verb. to glitter
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A word for “ray of light” in The Etymologies of the 1930s derived from the root ᴹ√AKLA-R (Ety/AKLA-R).
Conceptual Development: ᴱQ. alka “ray” appeared in the Qenya Lexicon of the 1910s as a derivative of the early root ᴱ√ḶKḶ; its primitive form ᴱ✶ak’lā indicated a historical development similar to that of The Etymologies (QL/30). The phrase ᴱQ. alkarissen oilimain “in the last rays of light” appeared in some of the versions of the Oilima Markirya poem from around 1930 (MC/221), but here the form was alkar as in alkar-issen = “ray-(locative-plural)”. The word alkar appeared in one of the glossaries of Oilima Markirya drafts with the translation “shining, light of day” (PE16/75). By The Etymologies of the 1930s, however, the form and meaning seem to have reverted to alka “ray of light” (see above).