Round White Pill with G over 1, Separated horizontally by a line.
Glyburide 1.5 mg. Used to treat diabetes. Your text description matches a text description of a different source that I have. I have photos of neither, so it's hard to be sure.
I asked this same question a while back- I think it is from the vet as I found it in a box of my dog's meds...But, I have never found out for sure. If you DO find something for sure, please post so I know as well. Thanks!