Bharpring asked:
> "Fancy button. Can anyone tell me what this button may have been used for or who would have worn it? I have never seen one like this."
I'll expand on Grasshopper's correct ID of your button, to answer your questions. Your button is from what button collectors call "The Golden Age" of gilted (gold-plated) metal buttons. The development of machines for mass-producing very ornate stamped-brass 2-piece buttons enabled craftsmen to attain the highest art in metal button-making. The firm of Benedict & Burnham is noted by collectors as one of the most-skilled button manufacturers of that era. When you see a particularly ornate and heavily gold-plated button from that time-period (1830s/40s), it is very likely to have a Benedict & Burnham backmark.
Answer to "Who would have worn it?"
Your beautiful "Geometric-Pattern" gold-plated button was made for use on higher priced fancy civilian coats and jackets, usually produced by a Tailor rather than being mass-produced at a factory. Being triple gold-plated, and there being a good number of these buttons (not just 4 or 5) on the coat or jacket, it would have been purchased by a fairly wealthy person.