This is an 6.25 inch Fiestaware orange uranium glazed plate found in an antique shop. This plate does have a small crack running halfway across the top. The practice of using uranium as a glaze pigment was very popular from the 1920's up until the mid 1940's when the government stopped the use of it in the civilian market. Radioactive pieces like this can be found in antique shops in the United States.
Pieces like this give off a lot of alpha and beta radiation with some gamma. The radiation reading in CPM (counts per minute) was made using a Radeye B20 radiation detector. The reading represents all the