silver floral decorated glass plate

Shown in the first pics with a tablespoon for size reference, here's a clear glass plate with rim decoration on the topside that appears to be actual silver plating that's been etched away to form the design pattern of flowers, leaves, and stems. It appears a dull light gray in color from underneath (pic 2) and the top is nearly universally tarnished to near black, but a few spots can be seen if looking close at the last two pics where the 'black' actually reveals its silver color coming through, and rubbing a little bit with a finger starts to brighten it up too.

There aren't any markings anywhere on it that I've recognized so far, thus I know nothing more about it. Anybody else??