Lots of looks, but no answers yet. I suspect that's because "ancient" is in the title, and the thread is therefore attracting the wrong experts. Let me edit it to include "Indian" in the title, since I'm pretty sure it's not ancient, but rather mediaeval or modern India.
At 0.75 grams, my best guess to identity is a 1/16th rupee.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis