A die based on the "Gyroelongated square dypiramid", one of the 8 convex deltahedra. This die features 16 equilateral triangle faces, but it cannot rest on the 8 faces which make up the two square pyramidal caps (those decorated with trefoils). So it works as a D8. The 8 "good" faces make up a square antiprism, and are labelled with symbols corresponding to the numbers 1-8 according to the number of their edges:
1=circle, 2=half moon, 3=triangle, 4=square, 5=house, 6=butterfly, 7=Christmas tree, 8=star.