Diamond block pattern pressed glass tray or serving plate in pretty pink, 1940s vintage Windsor pattern, Jeannette glass.
This is 12 1/2" across the handles, about 8 1/2" across the plate area. This doesn't look as though it's had a lot of use - it has very little scratching, no chips or cracks.
There is some roughness to the mold edge at the handle rims.