JD from Santa Barbara sends me two pieces of bright yellow Vaseline glass, both of which were once part of a desk set. You see an ink well and a paperclip bowl. Originally, the set would have been complete in yellow glass: a pen tray, a nib box, a letter holder, a stamp box, a blotter roller and two blotter weights for a desk blotter pad. This was a proper office gift.
If JD had a black light (UV), he would be scared. The glass would glow an ominous sickly green – showing evidence of uranium, usually in trace levels of 2% by weight uranium, but some maleficent glassmakers included up to 25% uranium. After the 1940’s, when uranium was stockpiled for our counter-attack (some thought) against the Russians, Vaseline glass was no long produced. Uranium today is still used in scientific glass.
If JD had a Geiger counter on his desk, it would click, showing “above background” radiation. Martin Klaproth (1743-1817), an experienced glassmaker, would have been proud – he discovered uranium in the 1700s. He would have loved to see J.D. exposed to radioactivity.
The fashion for this glass, which can range from yellow to yellow-green, began in traditional glassworks in Bohemia (now Austria). In 1840, Baccarat in France caught on to the unique color, producing their own brand of Vaseline glass, christened Chrysoprase, after its resemblance to rare chalcedony, a form of silica (quartz and monazite) mineral, gaining its green color in nature from nickel oxide. The glass earned the name Vaseline because of the color resemblance to the commercial entry to the market, contemporaneously, of that petroleum jelly.
Resembling petroleum jelly in its viscosity, Craftsmen discovered that the addition of uranium to glass allowed them to fire the glass at intense heat; the micro-crystallization also enabled glassmakers to produce oily or greasy looking depths to the glass. Some Vaseline glass can fool a collector into thinking he/she owns a piece of porcelain it can appear so opaque. And unlike lower-fired glass, it is very hardy, so pieces such as JD’s still survive today.
Yet that scientist in the 18th century simply rediscovered the use of uranium in glass: the earliest known use dates from 79AD, in glass mosaics found in a Roman villa on the Bay of Naples, discovered by an Oxford don in 1912.
As late as the 1920-1930, this radioactive glass was manufactured and collections showed up named green “Depression Glass,” or the rare and valuable Anglo-American blend of pink and yellow opaque glass called “Burmese” glass, or the imitation jade (usually fraudulently labeled real jade, made in China) called “Jadeite” glass, and the tableware called “Custard” glass.
Surprisingly rampant chemical experiments occurred in the mid to late 19th century: glass manufacturers capitalized on the growing middleclass market for a loaded, beautifully presented middle class table, for the first time available for middle class buyers. Previously only the very rich could afford glass in abundance. Mid-19th century glass was molded in a factory and NOT hand blown, piece by piece; the mechanization of glass made it a democratic medium, in demand as new brides’ gifts. And what a divergence of forms were produced. The ubiquitous banana boat and the pickle caster date from this period. Every table had to have three sizes of glass goblets as well as glass side dishes for fruit and cake. Centerpieces to hold fruit of pressed glass came into vogue as well as mass produced sherbet stemware.
Although this glass won’t kill you, collectors are usually delighted when someone notices they in fact collect uranium in a trace form. Glass bead wearers beware; many yellow or green beads from the earlier 1900s contain uranium, as well as MOST collectible children’s marbles from the earlier 20th century. I'm shocked to think that not only were children’s marbles fraught with traces of uranium but most kid’s toys of cast iron were painted with lead paint.
JD’s pieces are worth $150 each, but the rarest form of American Vaseline glass was made at the Boston and Sandwich Glass Co. in Massachusetts in the mid to late 19th century. A pair of Vaseline Sandwich small vases can sell for as much as $1,500 for a pair.
Certified appraiser for estates, inheritances and trusts.
Dr. Elizabeth Stewart's column appears every week in the Salon & Style section of the Santa Barbara News Press. Email her your questions and high-resolution photos at ElizabethAppraisals @ gmail.com
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