The word marble was first used in a twelfth-century religious text, where it was spelled marbra. Subsequent forms included Marbre, marbyr, and maber, until more recognizable spellings like marbell and marbel were adopted in the 1500s. The r changing to an l is pretty weird here because English has distinct liquid consonants that don't get confused much; the most likely explanation is that the word was influenced by a Germanic term that was lost to the ages. Marbra, through Old French, comes from Latin marmor, which further is from Ancient Greek marmaros, meaning "shining" or "sparkling" (this possibly has something to do with marble deposit being on the coast of the sea). Marmoreal, a literary word meaning "made of marble", is a cool remnant of this past form.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.