Chinese Happiness Symbol Pin Brooch HK Silver Costume Jewelry

Chinese symbol for happiness adorns this pin which is signed SILVER HK on the back. Not sure if this is actual sterling silver or what the HK stands for unless it stands for Hong Kong.

The pin appears to be black lucite. NOT stone. The lucite has a slight wave to it. Tried to show it in the third photo. Can only be noticed when held on an angle. Has the old "c" style clasp. Measures just under 1 1/2" long. Some scratches on the back. Perhaps this was a souvenir or import piece. Sold as is.