Jenna Gilley, Associate Curator of Exhibitions
Silver and gold, silver and gold… as the holidays quickly approach, I am growing more aware of the festive colors of the season. Silver and gold, red, green, and blue adorn our streets and homes in flashing and glistening bursts. FWMoA’s new hallway displays are also following suit; examples of silver wares from over three centuries are now on view, along with gilt decorative treasures from the turn of the 20th century.
One of the most enchanting examples on display is our growing collection of iridescent glass. Increased archeological explorations in the 19th century uncovered ancient glass examples from Egypt and Rome, some with a stunning rainbow sheen. This iridization was not an intentional treatment, but the result of centuries of weathering. Transfixed by its effect, modern makers like Loetz, Tiffany, and Steuben hoped to replicate this process in their decorative glass wares. At first, the effects mimicked the subtle ancient examples quite closely, but as time went by, makers experimented with bolder and more unusual colors. After many years of trial and error, each company developed their own highly secretive chemical formulas to create stunning, distinct treatments.


One impressive example on display measures over a foot tall and almost a foot wide and features the distinct “aurene” Steuben treatment. At first glance, the piece appears primarily gold, but as one looks from other angles, one side looks blue while the base has a deep red hue. This is one of the largest examples of aurene glass I have come across, and beautifully features the color’s multi-faceted nature. A similar treatment is evident on a pair of candlesticks and smaller, fluted vessels in the adjacent case. Aurene glass was first developed by Frederick Carder at Steuben Glass Works in 1904. At his previous company Stevens & Williams, Carter helped reintroduce colored glass into the European market. He also collaborated with Peter Fabergé, the notorious jeweler of the imperial family of Russia. After 20 years with the company, however, disagreements prompted Carder to emigrate with his family to Corning, NY and start his own glassworks. The business was dubbed “Steuben” after the county name (the more specific town name of “Corning” was already taken by the large Corning Glassworks, which remains a staple in glass art and production). Over the next 30 years, Carder would produce glass for America’s most prominent families—including the Rockefellers—and collaborate with the era’s top artists, including Thomas Hart Benton, Salvador Dalí, Henri Matisse, Georgia O’Keeffe, and Grant Wood. At age 96, he finally closed his studio and retired.
The beauty and science of aurene glass was perhaps Carder’s most enduring achievement. Derived from the Latin word for gold (aurum) and the English word “sheen”, aurene’s lustrous surface is created by spraying glass with stannous chloride or lead chloride and reheating it under controlled atmospheric conditions. The variations in temperature and time heated produce different surface colors. In 1905, Carter expanded his line of aurene glass to include green, blue, red, and brown.

Steuben’s works were often compared to that of the famous decorative object designer Louis Comfort Tiffany. Tiffany & Co. was notorious for its fluid, naturalistic designs paired with striking color combinations. Unlike previous glass companies, Tiffany mixed color into their glass using complicated chemical formulas instead of painting on its surface (despite this, Steuben actually featured a wider color range). Tiffany’s chemists disgruntledly noted that Mr. Tiffany had an irritating habit of taking full credit for the company’s chemical achievements, forgetting to acknowledge the actual chemists who painstakingly discovered and mixed each formula. Leslie Hayden Nash, the son of Arthur J. Nash, whom Tiffany invited to head up his glassmaking operation in 1890, bitterly remarked, “Don’t let anyone ever tell you that Louis C. Tiffany invented Favrile [a brand name for iridescent] glass. I personally made it for over 25 years, and he never saw the inside of the lab or even mentioned a chemical to me.” In a handwritten and locked formula notebook by Arthur Nash himself, a simple “LCT = Nuts!” marks one page. The notebook did, however, contain the secrets to unlocking Tiffany’s immensely protected formulas, which many other companies at the time tried to replicate or steal. A few include “ruby red”, achieved by adding gold into the mixture, and “blue luster”, containing silver nitrate, cobalt oxide, manganese, and even arsenic. While Steuben’s Carder did in fact know a thing or two about chemistry—he studied it in night school as a teenager–Louis C. Tiffany’s immense talent for business and creative design proved to be the driving force behind his company’s earlier popularity and its recent resurgence. Until it ceased production of colored glass in 1933, Steuben focused on simple vessel shapes that allowed the aurene treatment to shine (quite literally), but it did not have the same fanciful flourish as its competitor.

Another glass example in the case also features an iridescent treatment, this time in an opalescent color palette. The Silberiris vase is a dimpled, light pink glass vase with an iridescent surface that shifts from pink to blue, produced by the Czech Loetz Glass Company. The “silberiris” line was produced by Loetz from 1899-1904 and featured a multitude of iridescent finishes, often paired with exotic shapes and applied silver decoration. This particular example features a winding silver iris motif in the popular, languid style of Art Nouveau. Inspired by Tiffany’s Favrile glass exhibited in Bohemia and Vienna, in 1897 the owner of Loetz Glassworks, Max Ritter von Spaun, became convinced that his company should adopt the new Art Nouveau style, and entered into a prosperous and innovative era. While Loetz began by copying Tiffany’s iridescent glass they soon evolved their style and technique, creating lustrous, wavy effects of their own. This new style was given the name ‘Phänomen’ glass and was exhibited alongside Tiffany, Gallé, Daum, and Lobmeyr at the Paris Exposition Universelle in 1900, eventually winning a Grand Prix.

As time continued, as with many trends, everyone wanted a piece of the iridescent Tiffany-esque glass craze. Sometimes called rainbow glass, taffeta glass, or “poor man’s Tiffany,” carnival glass was first produced in 1908 by the Fenton Art Glass Company using iridescent metallic salts poured onto hot glass during the production process. The new manufacturers set their sights on the middle class, and offered their wares up as colorful prizes at the local carnival, hence how the nickname stuck. This marketing campaign turned out to be genius, and carnival glass boomed. In the 1970s, collectors returned to the whimsy and allure of carnival glass; thus, today, many of us encounter iridescent glass in the form of novelty in the homes of our parents or grandparents. Whether in the form of a funky carnival candy dish or a masterful Tiffany lamp, iridescent glass continues to spark delight over a century after its creation.
Looking for things to do over the holiday? Visit FMWoA during our normal operating hours, Tuesday-Saturday 10am-6pm; Thursday 10am-8pm, and Sunday 12pm-5pm. Closed New Year’s Eve, New Year’s Day, Christmas Eve, and Christmas Day.
Further reading:
Tiffany & Co’s formulas: https://www.tms.org/pubs/journals/jom/0709/byko-0709.html
Frederick Carder and Steuben’s history: https://steubenglass.org/about/
Loetz history: https://www.loetz.com/history
How iridized glass is made: https://www.youtube.com/watch?v=PIHXOq9hE0U (process begins at 2:00)
Great information — thanks for sharing.
Speaking as a Fort Wayne collector & researcher of iridescent Nouveau/Jugendstil glass from 1890’s – 1912-ish, I would say that Loetz is the undisputed master of hot-finish iridescence.
Though nice, the Loetz piece presented here is largely forgettable in terms of their designs. It is hard to tell from photos here, but it is doubtful that “Silberiris” is type of this decor. The term silberiris was used by Loetz to denote yellow crumbs with metallic contents, which gave iridescence to wherever it was applied during the hot finish process. The milky/pearly-looking ground color this piece exhibits something like what is referred to as “Thea.” You can check that by putting a blacklight on it, as the contents of all pieces in Thea ground allow it to glow green in ultraviolet. When seen from the inside-out, pieces which are silberiris appear yellow in color.
It is doubtful there will ever be glass that tops the finishes Loetz made exclusively for Bakalowitz circa 1901 – 1905. Some fine examples of Loetz’s most astounding work can be found by googling:
“Loetz PG 358”, or
“Loetz PG 85/5054”.
These are the decor “names” of a couple of their best.
Other lesser-mentioned firms, like Wilhelm Kralik Sohne, Fritz Heckert Kunstglas, and Ferdinand Von Poschinger also produced work which, in my opinion, far outshines British and American firms, but to a lesser quantity.
If there is a desire to have more pieces from the era, I’m open to discussing it, and am right here in Fort Wayne. I have been displaying some of my pieces on Youtube, and have documentation to support attributions.
Best wishes.
This was great information, thanks!