The reason we call it fiery opalescent over here. The conditions under which you photographed your glass had a lot to do with the effect I think. So I tried to mimmic your conditions. Although the creamer is not as dense? [for lack of a better term] in opalescence as your vase. Some success achieved and managed to isolate the most dense area, the pontil, and a nice purple red much desired by amberina collectors appeared. The lacy plate an after thought, but does show the effect in a small way, purely by accident.