Is the letter J used in ancient Roman inscriptions of (roughly) the classical era? If yes, in what kinds of contexts?
I am under the impression that using I for vowels and J for consonants is a distinction that came about in the medieval times. But this does not rule out the Romans sometimes carving their I with a notable hook so that it looks more like J. My impression is that using J (or something closer to it than I to the modern eye) is rare and unsystematic, but I think I have seen it a couple of times, both in text and and numbers. Unfortunately I have no references or photos to back me up, so I worry I might misremember.
Perhaps a more careful formulation: What is the closest thing to the modern letter J found in Latin inscriptions of the antiquity? (In this case I think a photo or a drawing would be nice, especially if it contains visually dissimilar examples of I and J.) The letter can be used for any sound; I am not looking for a distinction between vocalic and consonantal use but for a letter that looks like J. I want to focus exclusively on text written by an ancient hand to rule out any later editorial effects. I assume that if there are any examples, they are to be found in CIL, but I am not sure whether I can search for a single letter and whether CIL would make a distinction between I and J if one I looked a little like a J.