I researched this mirror for hours online, but sadly enough, the only lead I found was on ebay. Various "buy it now" vendors offer a "reproduced" version of a "Vintage Chinese hand mirror designed in 1878 (Qing Dynasty) in China" for around $20 (SEE LAST PHOTO). Some of these replica mirrors initially looked close to what I have, though once I started to examine mine closer I found some noticeable differences. Most apparent was that the back of my mirror has what looks like a crouching Buddha carved in the same kind of stone as the handle. And overall, the quality, detail, and intricacy of my mirror seems to be considerably better than the ebay replicas.
But I guess the short answer is I have no educated idea as to what I've got and how much it's worth. I just saw it at the thrift store and thought it was pretty, so I bought it!
I would greatly appreciate anyone's help in trying to identify this mirror.