Ivo, can it be a coincidence that this 'isolator' (aka 'insulator') vase looks a lot like some insulators? It reminds me of both the CD 117 style:
(http://glassian.org/Gallery/117/amp_dkaqua.jpg)
and also capacitor/transformer bushings:
(http://glassian.org/Bushing/capx1.jpg)

--ian