This is an antique Tibetan pendant that depicts Lord Vishnu.  This antique Tibetan pendant is inlaid with coral and turquoise and some green and brown stones that I’m unsure of.  I think that the pendant is possibly made of low grade silver.  It is quite large, measuring 3 1/8” by 2 5/8” - it weighs 55 grams (about 2 oz).  It is missing a number of surrounding stones, but the figure of Lord Vishnu is intact - please look at the photo.  The piece might benefit from a bit of a clean-up, but it looks fine under normal viewing.

I would think that this antique Tibetan pendant dates to the 19th century - it is an impressive example!