The columns shaft of this inimitable lamp is made out of a blue disk stripe, white and clear spectrum baroque glass.
Please notice the parallel situation between my lights and the images of the blue grotto (see hyperlink at title). The edge of the agate represents the ceiling of the cave, and the crystal middle represents the cave entrance. The blue flood everybody can explain to themselves. On the last image I show the complete glass plate out of which the object blue grotto was made.
The fitting of the blue grotto, which is one of the classic destination was founded by the German author August Kopisch and the Artist Ernst Fries (1801-1833) in the year 1826. The people who once founded and lived in the area of the blue grotto called it "Grotto Gradola" up until that point. Because the entrance is small and its hard to find, the place was used for criminal activities. And it had the reputation of being used for witchcraft.
Today many people visit the grotto just because a German painter of the Romanticism was crazy about this 'blue'.
Mass of the lamp: height: 562mm (a little bit less than 2 feet), Width: 173mm, depth: 135mm
Mass of the agate: 152mm times 163mm, breadth: 5mm