As shown, exquisite Lucite square dish with cut circular inside.
Embedded in four sides with shell slices.
Measurements are: 6 1/8th " x approximately (just under) 6 1/8th "
Height is 3.5"
Typical age stress marks  (not overly pronounced ) as shown in picture #9 and what you would expect to see in vintage Lucite.
Really chunky, heavy statement piece (weights 3.5 pounds)