Fueled by explorations and archaeological excavations in Africa, Asia and the Mediterranean, art during the Victorian period was influenced by ancient forms and motifs. A perfect example is cameo glass – an ancient technique revived during the Victorian period – with figures from Grecian mythology. Additionally, it seems that antiquities collectors of the time were attracted to the iridescence of ancient glasses, which was then mimicked by Victorian art glass artists. You can see an example of this in Tiffany’s Cypriote vase, which mimics the pitting found in archaeological glass as well as the iridescence.
As an archaeologist, I’m as interested in the ancient glass that influenced the Victorians as I am by the art glass itself. Now, I use Raman spectroscopy to study chemical residue on stones that were used to cook food. Spectroscopy analyzes the chemical components of an object by looking at how molecules vibrate when they are hit with light. While I look for organic residue, it can also be used to examine inorganic minerals. It is just one method that scientists use when trying to figure out what an unknown substance is.
Now, obviously we don’t have a lot of information about how ancient Romans, for example, made their glass. It’s been a long time and if there are records of how it was done, they have been lost. But we also don’t have a lot of information about how Tiffany or Steuben made their glass – while the basic recipes were recorded, detailed notes on the processes were not. It’s like if someone noted that bread was made with flour, yeast, and water, and neglected to mention the importance of kneading and letting dough rise. So what I think is cool is that a lot of the methods archaeologists use to study ancient glass are the same methods used by art historians to study these Victorian pieces.
So let’s look at the iridescent quality that Victorians seem to have liked so much. The iridescence in ancient glass was accidental. When the people had used their glasswares, they had been ‘regular’ glass. But left buried over time in the right environment, the glass reacted with the minerals in the ground to form a sheen on the surface of the glass. The weathering process can have a lot of different effects, and has been studied extensively by scientists, usually so they can figure out the best way to preserve ancient glasses from further deterioration.
The exact process that the glass goes through in weathering is unknown, but it seems water is the main requirement, and different minerals in the soil and/or water produce different effects. It seems that the outer portion absorbs water and this somehow produces layers. Different chemical processes can go on these layers – minerals can be leached out or they may recrystallize. This in turn changes the way light passes through the glass, and iridescence is one of visual effects it may create. On the other hand, the iridescence found on Victorian period glass was a purposeful creation to mimic ancient glasses. This was done by applying a film on the glass while it was still very hot.
In 1913 Tiffany filed a lawsuit against Steuben for infringing on his trademarked “Favrile” style of iridescent glasswares, which he had patented in 1890. Steuben had patented his Aurene iridescent glass technique in 1904. The lawsuit was dropped – a) iridescent techniques had been created before, b) the surface decorations were different and c) the forms of the glassware were distinctive. This peacock vase is an example of Steuben’s iridescent work.
This is borne out in the scientific analyses. Stueben’s art glass reflects a standardized production regime using less expensive additives to get similar effects in his glasswork. Tiffany’s art glass, on the other hand, reflect the experimental nature of his program – there is a greater range of variation in his glass formulations and he used more exotic materials.