Difficult to tell without a little more detail. Can you post a picture of the back of the case? Best would be the inside of the case back (or the mechanism behind the case back) but you'll probably need to bring it to a watch-maker to open it up and see.
yes I believe it's authentic. seen quite a few of them and were popular in the south pacific but surely elsewhere too. quartz with a snap back.
Tis real. The case style was originally marketed in 1987 as the part of the "Symbols"collection - ankh, yin/yan and sun. Afterwards the case design was coupled with dress dials, the black ones being competition for the Movado Museum watch, which was very much de rigeur in the late Eighties. The model number can be obtained by opening the case back. When you get it done take a pic of the movement. It will be quartz. Yours is well worn, the facets on the bezel and bracelet pretty well non-existent. A nice piece of Eighties design, which will be appreciated by generations beyond the current ones. Cheers Desmond
As an addition to the above, on the solid gold models in this series the case number is occasionally stamped on the bracelet clasp too so can be inspected without removing the back. This might not be the case here with a steel or mixed metal one though and is unusual on Omegas in general. Look for a 6 or 7 figure number, something like 395xxxx