No, it is not an insulator.
Its title is Purple Object by the glass artist Petr Hora. Created in 2001, it is Peter's first piece to enter the collection at the Corning Museum of Glass. It is made of cast glass, cut, and acid etched.
It is on display in the Sculpture Gallery at CMOG. I snapped this picture in early June, 2004 during a visit to the museum. If you are ever near Corning, NY, CMOG is worth the price of admission.