Month: January 2013

Identifying jade


To the Ancient Chinese, jade was more valuable than gold and called the stone of heaven. They considered jade to have special powers and symbolic meaning.

Though commonly thought of as green, jade can be found in different colors including white and red, and can be transparent to opaque. Jade is be one of two minerals, nephrite and jadeite. Nephrite is the jade the Chinese used, is more common and a touch softer than jadeite. Jadeite is more valuable.

The best way to determine if an item advertised as genuine jade is genuine jade is to take it to a knowledgeable gemnologist or geologist. However, the following are some simple tips that will help separate the real from crystal, glass and other faked jade.

** Jade is cold to the touch. Hold it to your face or in your hand It’s noticeably colder than glass. Plastic is typically warm.

** Jade is dense and heavy. It has heft in your hand.

** If there are air bubbles in the stone, it is not jade but glass.

** Jade can’t be scratched by steel.

** Jade gives a chime-like sound when it’s hit by anther stone. Many other stones give a dead thunk. The Chinese made flutes and other instruments from jade.

** Jade often has a shiny, greasy looking surface.

** Jade is usually super smooth. If it feels bumpy when you run your fingernail across is, it’s likely not jade.


Purchase a copy of Identifying Common Materials in Antiques: A Pocket Guide

Jet black jet

Jet is a black fossilized material prized for its gem-like use in jewelry, including necklaces, brooches, pins and earrings. The term jet black, meaning as black as black can get, comes from jet. When Prince Albert died in 1861, his wife Queen Victoria famously wore jet mourning jewelry and jet was popularly used in general for Victorian era mourning jewelry.

Primarily originating from underneath Whitbey England, jet is fossilized wood, often well over one hundred thousand years old. Though not particularly attractive when it’s mined from the ground, it is easily carved and polished to a gem-like black. You can sometimes see patterns from the original tree.

Queen Victoria's daughter Princess Louise wearing jet beads

Queen Victoria’s daughter, Princess Louise, a wearing jet bead necklace

Identifying Genuine Jet. Jet and black glass are sometimes mistaken for each other, but glass is cold to the touch while jet is warm. Jet is light and floats or sinks slowly in water. If you rub jet on unglazed pottery or a sidewalk is will leave a brown/black streak.

Miscroscopy in prints authentication

A microscope is often used by an authentication expert to date the kind of printing used to make both photographs and ink-and-printing-press prints. Modern reprints and counterfeits are often identified because the microscope shows the printing is too modern. An 1870 print couldn’t have been made with a printing technology invented in 1985.

For an example, the picture below what ‘elecrostatic’ printing looks like under the 100X zoom power of a microsope. Electrostatic printing is the modern technology used to make Xeroxes, photocopies and on standard home computer laser printers. Large numbers of reproductions of antique prints and photos have been made using this type of printing.

Under the microscope, the modern elecrostatic prints are easily identified by the unique and quirky pattern of the pigment (ink). In this printing process the lines are made up of many tiny dust-like grains of pigment that have been fused (melted) to the paper. When you handle ink jet cartridges you will notice the pigment/ink is dusty and dry, and can get all over the place if you are not careful. In the printing process not all the grains of pigment make it to the intended area before being fused, so the print is identified by the many stragglers outside the lines. It looks like it needs a dusting.  

If an ‘1880 lithograph’ or ‘Renoir etching’ looks like this under the microscope, it is clear the print is a modern reprint.

home computer laser printing at 100x magnification

home computer laser printing at 100x magnification

A common misperception about limited edition prints

Some prints, photographs and other types of art and collectibles are limited edition numbered: say, 1/50 (1 of 50 made), 2/50, 3/50 …. 50/50. Some collectors feel that the first print or photograph or figurine ‘off the presses,’ is the most valuable, and, as one might expect, pick one that is numbered 1/50. The thing they don’t realize is that the works are rarely numbered is the order of printing. The numbering and signing was often done well after the printing or manufacture. For example, Marc Chagall would go through the stack of prints, picking out which ones he liked and sign and hand numbering the ones that met his approval. He wasn’t trying to keep things in order of printing. Thus, the print numbered 1/50 may or may not have been first one off the printing press. Print # 12/50 or 6/50 may have been the first. And there’s no way to know for sure.

The difference between a fake and a forgery

A forgery is an item that was made to fool others into believing it is something it is not. This includes counterfeits, but also made up items like a ‘newly discovered’ Rembrandt painting.

On the other hand, a fake is an item that is seriously misidentified or who’s identity is seriously misrepresented. This includes forgeries and counterfeits, but it also includes items that are innocently misidentified by collectors or sellers who are uninformed.

When in doubt about a seller or maker’s intent, it’s best to call a bad sale or auction item a fake instead of a forgery or counterfeit. All three words mean an item is not genuine, but forgery and counterfeit implies intentional illegality.

Using a black light to identify many fakes

pocket LED black light

pocket LED black light

An inexpensive and easy to use longwave black light is a great tool for quickly identifying reprints and fakes of Pre World War II paper material. This includes trading cards, photographs, programs, posters, postcards, tickets and anything made of paper.

A black light is effective in identifying of many, though not all, modern paper stocks.

Starting in the late 1940s, manufacturers of many products began adding optical brighteners and other new chemicals to their products. Optical brighteners are invisible dyes that fluoresce brightly under ultraviolet light. They were used to make products appear brighter in normal daylight, which contains some ultraviolet light. Optical brighteners were added to laundry detergent and clothes to help drown out stains and to give the often advertised `whiter than white whites.’ Optical brighteners were added to plastic toys to makes them brighter and more colorful. Paper manufacturers joined the act as well, adding optical brighteners to many, though not all of their white papers stocks.

A black light can identify many trading cards, posters, photos and other paper items that contain optical brighteners. In a dark room and under black light optical brighteners will usually fluoresce a very bright light blue or bright white. To find out what this looks like shine a recently made white trading card, snapshot or most types of today’s printing paper under a black light.

If paper stock fluoresces very bright as just described, it almost certainly was made after the mid 1940s.

It is important to note that not all modern papers will fluoresce this way as optical brighteners are not added to all modern paper. For example, many modern wirephotos have no optical brighteners. This means that if a paper doesn’t fluoresce brightly this does not mean it is necessarily old. However, with few exceptions, if a paper object fluoresces very brightly, it could not have been made before World War II. 
It is important that the collector gain practical experience. This means using a black light to examine and compare the fluorescence of a variety of items. With photographs, make sure you shine the black light on all sides and edges. This is because the gelatin or other coating on the front of the paper often prevents the front from fluorescing.

The beauty of this black light test is you can use it on items you aren’t an expert on. You may be no expert on 1920s German Expressionist movie posters or 1890s Canadian fishing industry pamphlets, but you can still identify many modern reprints.

Tagging art microscopically

magnified microdot with identifying serial numbers

magnified microdot with identifying serial numbers

Art, artifacts, collectibles and other valuables are often security marked in case of theft, loss, dipsute or other later need to identify the item and/or owners. The markers range from overt holograms and serial numbered stickers to invisible tags, and allow the marked items, and often the rightful owners, to be identified.

An interesting covert marking system uses microdots. Microcodots are miroscopically small metal discs that have identifying information microetched on them. The information can be read under a microscope.  The dots can be the size of standard printed perdiod (.). The etched information can be a unique serial number that identifies the object’s owner. Applied via clear adhesive to a valuable painting or sculpture, the dots will go completely unnoticed by the average thief, but can be used to trace the item back to the rightful owner.

Microdots and related covert ‘shrinking down text’ is an old time application. German spies used microdots to covertly pass information during WWII.  Even as early as the 1870 Franco-Prussian War, carrier pigeon messages were photographically shrunk so the bird could carry more text.

Aleatory art

Any path is right, if— as according to Bach– it leads to the divine”— music historian Paul Epstein on J.S. Bach’s fugues, to which Bach never gave a playing order.

Aleatory art is art where the finished result is substantially out of the artist’s hands. It can involve chance or the musicians’ or audience’s choice. Many games are aleatory. Monopoly involves the roll of the dice. Poker involves the shuffling of the cards. Aleatocism in art can create fresh, inventive, unexpected results. If the results defies the conventions of plot, narrative and order, that’s the point.

J.S. Bach’s little fugues are aleatory in that he never communicated which order the short musical pieces should be played. They can be played or listened to in any order, take your pick, randomly program the CD player. In the above quote, Epstein is saying an overall sublime aesthetic result justifies whichever fugue order lead to it. It’s reminiscent of the Hindi saying, “Any path that leads to God is correct.”

Novelist William S. Burroughs used the so called cut-up aleatory technique. Pages of text were physically cut up and randomly pieced back together, sometimes with text by other authors, creating new and often profoundly surreal meaning and narrative. Burroughs believed this type of collage more closely represented the human experience. Despite the conceit of linearity, humans don’t think or experience things linearly, one’s thoughts constantly flipping back and forth between past, current and future. Random little events and objects trigger memories and provoke speculation of the future. When you consider buying a can of beans in the grocery isle, you think about past meals and the future meal where these beans might be used. The human ability to identify flowers, shoe brands and people involves comparing the present to memory. Human intelligence and reasoning involves mentally flipping back and forth through time.

Even with a physically bound paper book, the reader chooses the order in which the book is read. Whether or not they realize it, readers are as responsible for the order as the author, though the author usually gets the blame.

William S. Burroughs said the chapters of his novel Naked Lunch could be read in any order. That a reader read them 1, 2, 3 had nothing to do with him.

Lab experiment becomes art

Edgerton photo of woman and hummingbirds

Massachusetts Institute of Technology electrical engineering professor Harold Edgerton became world famous for his invention of the strobe light and stroboscopic photography, the latter a form of ultra high speed photography using strobe lights. Edgerton was studying turbine engines in his 1930s Cambridge Massachusetts lab and wanted stop-action images of the engine in motion. However, camera systems of the day could not take such high speed photographs, as their shutters opened and closed too slowly. A turbine engine is way faster than a camera shutter. Instead of ‘clicking’ photos of high speed objects, Edgerton’s new process turned off the lights, opened wide the camera’s shutter and, in the darkness, shot quick flashes of light from his strobe light onto the moving subject. The camera film would thus show instantaneous bursts of action.

With this stroboscopic photography, Edgerton was able to capture a high speed world never before seen by human eyes: a hummingbird’s wings in mid flap, a speeding bullet piercing a playing card, a splash of milk in mid splash.  Today, many of Edgerton’s surreal, fantastic and sometime beautiful photographs are considered to be works of art.


Curious physical forms of ancient money

coin77grosseMessermuenzeMoney has taken unusual material forms over the years. Cows, sheep and goats were first used as currency thousands of years before Christ.

Cowries, the shells of a mulluscs, were a popular form of currency for many years. Bronze and copper cowrie imitations were manufactured by China at the end of the Stone Age and can be considered some of the earliest forms of metal coins.   Pictured on the left are circa 1000BC gold cowrie coins.

Metal ‘tool’ money, such as knife  and spade shaped monies, was also used in China. These early metal monies developed into primitive versions of round coins.   Pictured on the right are ancient Chinese knife moneys.  The Chinese also used leather strips with text as money, moving close to the first paper bills.