This is a vintage gold gild and white tea cup.
The scalloped rim porcelain cup is gold gild on the back, and has a white band around the front with a gold-tone vine, applied gold-tone and white flowers, a gold-tone bird, and reads "sister" in gold-lettering.
It measures 3.25" tall, 4" wide including the handle, and 3.25" in diameter. On the bottom is the number "40".
This cup is in pre-owned condition, but has some small chips on the applied flower and one on the bottom rim.