Louis C. Tiffany admired the shimmering surface of Roman glass, and scientists working in his factory succeeded in imitating the natural iridescence.

To achieve the effect, the hot glass is sprayed with tin chloride that will form a layer of tin oxide (SnO₂) on the surface. The tin oxide layer on glass acts like a layer of oil on water, and the addition of silver nitrate to the batch increases the brilliance of the iridescence.?This bowl features Tiffany’s man-made iridescence and imitates the organic flow of lava. One natural form of glass is the volcanic rock obsidian.