Uranium glass is
glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling ( quenching ...
which has had
uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
, usually in oxide
diuranate form, added to a glass mix before melting for colouration. The proportion usually varies from trace levels to about 2% uranium by weight, although some 20th-century pieces were made with up to 25% uranium.
First identified in 1789 by a German chemist, uranium was soon being added to decorative glass for its fluorescent effect. James Powell’s Whitefriars glass company in London, England, was one of the first to market the glowing glass, but other manufacturers soon realised its sales potential and Uranium glass was produced across Europe and later North America.
Uranium glass was once made into tableware and household items, but fell out of widespread use when the availability of uranium to most industries was sharply curtailed during the
Cold War in the 1940s to 1990s. Most such objects are now considered antiques or retro-era collectibles, although there has been a minor revival in
art glassware. Otherwise, modern uranium glass is now mainly limited to small objects like
bead
A bead is a small, decorative object that is formed in a variety of shapes and sizes of a material such as stone, bone, shell, glass, plastic, wood, or pearl and with a small hole for threading or stringing. Beads range in size from under ...
s or
marbles
A marble is a small spherical object often made from glass, clay, steel, plastic, or agate. They vary in size, and most commonly are about in diameter. These toys can be used for a variety of games called ''marbles'', as well being placed in mar ...
as scientific or decorative novelties.
Appearance
The normal colour of uranium glass ranges from yellow to green depending on the
oxidation state
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...
and concentration of the metal ions, although this may be altered by the addition of other elements as
glass colorants. Uranium glass also
fluoresces bright green under
ultraviolet light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...
and can register above background radiation on a sufficiently sensitive
Geiger counter, although most pieces of uranium glass are considered to be harmless and only negligibly
radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...
.
File:Uranium glass beads, black background.jpg, Modern uranium glass beads (black background)
File:Uranium glass beads, UV light.jpg, Modern uranium glass beads (UV light)
Vaseline glass
The most common color of uranium glass is pale yellowish-green, which in the 1930s led to the nickname "Vaseline glass", based on a perceived resemblance to the appearance of
Vaseline
Vaseline ()Also pronounced with the main stress on the last syllable . is an American brand of petroleum jelly-based products owned by transnational company Unilever. Products include plain petroleum jelly and a selection of skin creams, soa ...
-brand
petroleum jelly as formulated at that time. Specialized collectors still define Vaseline glass as transparent or semi-transparent uranium glass in this specific color.
Vaseline glass is sometimes used as a synonym for any uranium glass, especially in the United States, but this usage is frowned upon, since Vaseline-brand petroleum jelly was only yellow, not other colors. The term is sometimes applied to other types of glass based on certain aspects of their superficial appearance in normal light, regardless of actual uranium content which requires a
blacklight
A blacklight, also called a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave (UV-A) ultraviolet light and very little visible light. One type of lamp has a violet filter material, either on the bulb or in a sepa ...
test to verify the characteristic green fluorescence.
In the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
and
Australia, the term Vaseline glass can be used to refer to any type of translucent glass.
Other colors
Several other common subtypes of uranium glass have their own nicknames:
* Custard glass (opaque or semiopaque pale yellow)
* Jadite glass (opaque or semi-opaque pale green; initially, the name was trademarked as "Jadite", although this is sometimes over-corrected in modern usage to "
jadeite")
*
Depression glass
Depression glass is glassware made in the period 1929–1939, often clear or colored translucent machine-made glassware that was distributed free, or at low cost, in the United States and Canada around the time of the Great Depression. Depres ...
(transparent or semitransparent pale green).
*
Burmese glass
Burmese glass is a type of opaque colored art glass, shading from yellow to pink. It is found in either the rare original "shiny" finish or the more common "satin" finish. It is used for table glass and small, ornamental vases and dressing table a ...
(opaque glass that shades from pink to yellow)
Like "Vaseline", the terms "custard" and "jad(e)ite" are often applied on the basis of superficial appearance rather than uranium content. Conversely, "Depression glass" is a general description for any piece of glassware manufactured during the
Great Depression regardless of appearance or formula.
History
Pre-industrial usage
The use of uranium glass dates back to at least 79 AD,
the date of a
mosaic
A mosaic is a pattern or image made of small regular or irregular pieces of colored stone, glass or ceramic, held in place by plaster/mortar, and covering a surface. Mosaics are often used as floor and wall decoration, and were particularly pop ...
containing yellow glass with 1%
uranium oxide
Uranium oxide is an oxide of the element uranium.
The metal uranium forms several oxides:
* Uranium dioxide or uranium(IV) oxide (UO2, the mineral uraninite or pitchblende)
* Diuranium pentoxide or uranium(V) oxide (U2O5)
* Uranium trioxide o ...
found in a
Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*'' Epistle to the Romans'', shortened to ''Romans'', a lette ...
villa on Cape
Posillipo
Posillipo (; nap, Pusilleco ) is an affluent residential quarter of Naples, southern Italy, located along the northern coast of the Gulf of Naples.
From the 1st century BC the Bay of Naples witnessed the rise of villas constructed by elite Roma ...
in the
Bay of Naples,
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
, by R. T. Gunther of the
University of Oxford
, mottoeng = The Lord is my light
, established =
, endowment = £6.1 billion (including colleges) (2019)
, budget = £2.145 billion (2019–20)
, chancellor ...
in 1912.
[Emsley, ''Nature's Building Blocks'' (2001), page 482] Starting in the late
Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...
,
pitchblende
Uraninite, formerly pitchblende, is a radioactive, uranium-rich mineral and ore with a chemical composition that is largely UO2 but because of oxidation typically contains variable proportions of U3O8. Radioactive decay of the uranium causes t ...
was extracted from the
Habsburg silver
Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...
mines in
Joachimsthal,
Bohemia (now Jáchymov in the
Czech Republic
The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
), and was used as a coloring agent in the local
glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling ( quenching ...
making industry.
Martin Klaproth (1743–1817), who discovered uranium, later experimented with the use of the
element as a glass colourant.
Usage
Glass fabrication
Uranium glass is used as one of several intermediate glasses in what is known to scientific glass blowers as a 'graded seal'. This is typically used in glass-to-metal seals such as
tungsten
Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isol ...
and
molybdenum or
nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ...
based alloys such as
Kovar
Kovar (trademark of CRS Holdings, inc., Delaware) is a nickel–cobalt ferrous alloy compositionally identical to Fernico 1, designed to have substantially the same thermal expansion characteristics as borosilicate glass (~5 × 10−6 /K betwe ...
, as an intermediary glass between the metal sealing glass and lower expansion borosilicate glass.
Modern production
Uranium glass became popular in the mid-19th century, with its period of greatest popularity being from the 1880s to the 1920s.
The first major producer of items made of uranium glass is commonly recognized as Austrian
Franz Xaver Riedel, who named the yellow (german: Gelb) and yellow-green (German: Gelb-Grün) varieties of the glass "annagelb" and "annagrün", respectively, in honor of his daughter Anna Maria. Riedel was a prolific blower of uranium glass in
Unter-Polaun (today
Dolni Polubny),
Bohemia from 1830 to 1848.
By the 1840s, many other
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
an glassworks began to produce uranium glass items and developed new varieties of uranium glass. The
Baccarat glassworks in
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
created an opaque green uranium glass which they named
chrysoprase from its similarity to that green form of
chalcedony
Chalcedony ( , or ) is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monocli ...
.
File:Fluorescent Uranium Depression Glass.jpg, Fluorescent
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, ...
uranium Depression glass
Depression glass is glassware made in the period 1929–1939, often clear or colored translucent machine-made glassware that was distributed free, or at low cost, in the United States and Canada around the time of the Great Depression. Depres ...
Image:U glass above.jpg, A uranium glass cakeplate glowing under UV light.
Image:U glass with black light.jpg, Uranium glass glowing under UV light
File:Uranium-glass-necklace.jpg, Uranium glass necklace, circa 1930.
At the end of the 19th century, glassmakers discovered that uranium glass with certain mineral additions could be tempered at high temperatures, inducing varying degrees of micro-crystallization. This produced a range of increasingly
opaque
Opacity or opaque may refer to:
* Impediments to (especially, visible) light:
** Opacities, absorption coefficients
** Opacity (optics), property or degree of blocking the transmission of light
* Metaphors derived from literal optics:
** In lingu ...
glasses from the traditional
transparent
Transparency, transparence or transparent most often refer to:
* Transparency (optics), the physical property of allowing the transmission of light through a material
They may also refer to:
Literal uses
* Transparency (photography), a still, ...
yellow or yellow-green to an opaque white. During the Depression years, more
iron oxide was added to the mixture to match popular preferences for a greener glass. This material, technically a
glass-ceramic
Glass-ceramics are polycrystalline materials produced through controlled crystallization of base glass, producing a fine uniform dispersion of crystals throughout the bulk material. Crystallization is accomplished by subjecting suitable glasses to ...
, acquired the name "vaseline glass" because of its supposedly similar appearance to
petroleum jelly. Today, a few manufacturers continue the vaseline glass tradition:
Fenton Glass,
Mosser Glass Mosser Glass is a company making handmade glass, founded in Cambridge, Ohio
Cambridge is a city in and the county seat of Guernsey County, Ohio, United States. It lies in southeastern Ohio, in the Appalachian Plateau of the Appalachian Mountain ...
,
Gibson Glass and
Jack Loranger.
U.S. production of uranium glasses ceased in the middle years of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
because of the government's confiscation of uranium supplies for the
Manhattan Project
The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project w ...
from 1942 to 1958. After the restrictions in the United States were eased several firms resumed production of uranium glass, including Fenton, and Mosser; though uranium was still regulated as a strategic material.
Following the Cold War, restrictions on uranium glass were completely lifted. During this time many older pieces entered the free market and new pieces continued to be produced in small quantities into the 2000s.
Riihimäki Glass produced uranium glass designer pieces after
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
.
See also
*
Carnival glass
Carnival glass is moulded or pressed glass to which an iridescent surface shimmer has been applied. It has previously been referred to as aurora glass, dope glass, rainbow glass, taffeta glass, and disparagingly as 'poor man's Tiffany'. The name ...
*
Depression glass
Depression glass is glassware made in the period 1929–1939, often clear or colored translucent machine-made glassware that was distributed free, or at low cost, in the United States and Canada around the time of the Great Depression. Depres ...
*
Fiestaware
*
Sievert
The sievert (symbol: SvNot be confused with the sverdrup or the svedberg, two non-SI units that sometimes use the same symbol.) is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing rad ...
*
Uranium tile
*
Sencer Sari
References
Further reading
These People Love to Collect Radioactive Glass ''Collectors Weekly''
External links
Uranium Glass – The Glass Association
{{DEFAULTSORT:Uranium Glass
Collecting
Glass compositions
Uranium