It is not uncommon today to find beads or other items of jewellery for sale at antique markets, or online auction houses, that are described as ‘cherry amber’. What is this material, and is it real?
Amber, the fossilised tree resin that is many millions of years old, can be found in various countries world wide. The best known is Baltic amber. This was formed about 35,000,000 years ago in the forests that covered an area that is today Scandinavia, the Baltic countries and the Baltic Sea. In some of the countries that surround the Baltic Sea amber is industrially mined and exported in large quantities -- especially from Lithuania, Russia and Poland. Baltic amber accounts for about 98% of all the amber on the market today.
Other countries that mine amber include the Dominican Republic, Mexico and Burma (now Myanmar), but the amount produced by all these countries is very small and all the mining is carried out by hand.
Transparent, red amber has long been considered special. In the eighteenth century it was much prized by the Chinese for working, and was intricately carved into small figures or scent bottles.
The material was, and still is, extremely rare and expensive. It usually occurs in small pieces, and from very, very few localities. How, then, can we find so much on the market today?
Many ambers look red if seen by transmitted light, that is, if viewed with the light behind them. Some Mexican amber can have a beautiful, deep red colour, and the rather dull brown amber of Borneo can take on a wonderful red hue when viewed this way. Historically, there may have been some transparent red amber in China, but it is believed that most of the red material carved there was imported from Burma. It was in this country that the real ‘red’ amber was found. Burmese amber – also called ‘burmite’ – occurs in various colours: clear golden, golden with streaks of reddish brown, brown, and rusty red. A piece of clear ‘red’ is rare.
Recently amber was found near Cape York, Queensland, Australia. A small percentage has a red body colour similar to that of burmite, but the find is still new and very little material actually finds its way onto the market.
Fresh, natural Baltic amber never occurs in a red colour, nor does it appear red by transmitted light, though it can acquire a reddish patina with age. The surface of the material oxidises and darkens, making the amber look anything from orange through rust red to brown, and usually opaque. Thus examples of Stone Age amber carvings that can be viewed in museums are normally dark in colour. If they were to be re-polished, it would be seen that this colour is only on the surface, and that underneath the amber is paler.
This phenomenon has been copied by treating Baltic amber. Most of the new Baltic amber on the market today has been processed in some way, and much of the treatment is perfectly acceptable. Altering the colour and clarity of amber is not a new idea. The Romans were treating Baltic amber to enhance it 2000 years ago. They could clarify opaque amber and darken its surface. To do this they boiled it in pig fat or rapeseed oil. Today we use more modern methods which are often closely guarded secrets. A basic process would consist of heating the cut and polished pieces of amber in an autoclave, which results in the material clarifying and the surface darkening to whatever shade is desired. A dark, reddish brown surface will appear as a red hue, and the material will look very red by transmitted light. The darkened surface can only be removed by re-polishing. This is often popularly termed ‘cherry amber’.
Unfortunately there are other materials on the market that are called red, or cherry amber, which are not amber at all, but are imitations or ‘simulants’. As red amber has always been sought after, it has been imitated in less expensive materials, notably plastics.
Red amber imitations were very popular in the early to mid twentieth century, when good quality fakes were mass produced in cast phenolic resin. Often called by the gem trade ‘Bakelite’, it is a phenol formaldehyde polymer which is closely related to Bakelite but formed by another process. The material was usually made into beads. There are, of course, variations, but often the opaque red beads are round or oval, whilst the facetted red beads are transparent.
It is worth noting that, while the clear red phenolic beads may imitate amber, the natural material never occurs in opaque red, so the opaque beads have been 'imitating' something that does not exist!
Phenolic resin beads, sometimes called 'Vinatge amber Bakelite'
The best way to identify red amber is by sight. When a light is shone through an opaque bead it is seen that the colour occurs in streaks, caused by the production method. (The plastic material was extruded in long rods which were later cut, shaped and polished). Although there may be swirls of opaque and transparent material in natural Baltic amber, it is not in lines and it is not red.
Opaque cast phenolic resin (often called 'Bakelite') ear-rings, and detail of the same viewed by transmitted light.
Objects that have been moulded will not show stripes of colour, but may show swirls. Like the extruded plastic, they may also contain occasional air bubbles, and although amber can naturally contain air bubbles these tend not to appear singly and they render the amber unsuitable for carving.
Total absence of any form of inclusion or blemish inside a row of clear, red beads is also a warning sign, as amber is seldom, if ever, totally free of inclusions. Plastic beads may be moulded instead of carved, so there may be a lack of signs of carving, and soft facet edges. But probably the best indicator with beads is the overall colour. If it is very uniform, the beads are unlikely to be amber, because, being a natural material, amber does not occur naturally in evenly coloured pieces.
Details of heat-treated Baltic amber, showing inclusions, and faded colour on facet edges caused by final polish (left), and
There are various tests for natural amber, but the only one that is completely non-destructive is to immerse it in saturated salt water and see if it floats. Having a specific gravity less than that of water, amber will float, whilst most plastics – phenolic resin included – will sink. This test cannot be used on jewellery that has been mounted as the metal mounts will cause the piece to sink. Further, a string of beads may be dragged down by the weight of the thread, or be falsely kept afloat by the air trapped in the drill holes of the beads, but if a necklace is quickly immersed and immediately sinks like a stone, it is a good indication that it is not real amber. (Note: Amber should be rinsed thoroughly in warm water after testing in salt water, to ensure that no salt is allowed to remain inside any possible cracks on the surface of the object, leaving a white residue when it dries).
Phenolic resin beads that have sunk in salt water, while a piece of natural amber floats.
Careful examination of an item can also show features such as surface blemishes, where the surface colour may have been scratched away, for example by the pin of a brooch, showing clear material beneath. This indicates that the item is heat-treated amber, though there exist today examples of yellow beads made of a mixture of powdered amber and plastic, which have a coating of red dye.
The two items illustrated below were purchased through an online auction. Described as antique Chinese carvings in red amber, they were offered with a starting price of about US$7, which alone made it highly unlikely that they were amber of any type, let alone red amber. The two ‘carvings’ proved to be high quality plastic mouldings, possibly hand finished. One had an air bubble on a corner, which had occurred in moulding. The red colour was a surface dye which could be partially removed with nail polish remover or acetone. (Usually plastic items have the dye added to the powdered raw material before it is moulded, so that the colour is even right through the material. )
Items sold as antique red amber carvings, which proved to be plastic imitations, and detail showing uneven surface dye.
Another test involves taking a scraping of material from an inconspicuous area and burning it, to judge by the smell of the burning material whether it is amber or plastic. This is destructive for the item being tested and potentially dangerous if the material proves to be an early, combustible plastic. A test often cited in online auctions is rubbing a suspected ‘Bakelite’ item with certain cleaning chemicals. This test is regarded as dubious, and at best inconclusive, as dyes in the Bakelite can alter the test results. It is also potentially destructive.
Infra red spectroscopy tests can be performed in a laboratory that can distinguish between various ambers, and ambers and plastics.
A new form of red amber is appearing on the market. Baltic amber is now re-constituted and processed with red pigment added – which results in totally transparent and completely evenly coloured 'amber'. There has been some uncertainty as to how the colour was produced, and whether it was by thermal process or by dye, but OG has now received confirmation. There are no signs of paler facet edges or of impurities in the finished product. It has a high luster and is very pretty, but it could be mistaken for plastic.
The appearance of this material makes it less easy to diferentiate by sight between cast phenolic resin and treated amber, unless of course the item is known to pre-date the new 'red amber'.
Red amber -- how was it treated? Section of Amber Room frame (left), and beads (right).
The material resembles some of the amber used in the newly built Amber Room in the Catherine Palace in Tsarskoye Selo in Russia. Here very clear large pieces in red and orange have been carved as intaglios, or facetted to shine like rubies. It is known that some of the opaque amber was given a surface dye, but whether the clear pieces were produced from pressed amber or not remains a mystery, though judging by its appearance it seems most likely.
......AND ANOTHER UPDATE
Yet another form of 'red amber' has appeared on the market. It is very even in colour and has no pale facet edges. First impressions suggest either plastic or re-constituted and dyed amber.
'Red amber' bracelet (left), surface colour removed with acetone (centre), and broken bead showing clear material and red coating (right).
When tested, some red colour could be removed from the surface with acetone. A broken piece proved to be completely clear inside with a coating of red dye. Labortaory tests gave results that the basic material is clarified Baltic amber, with a thin, synthetic coating. In the illustration it can be seen that the coating had been added after the beads were drilled as it covers the drill holes.
This material is being sold as autoclave-treated Baltic amber, with no mention of a surface dye.
A FURTHER TWIST IN THE CHERRY AMBER TALE: 'VINTAGE AMBER BAKELITE'
It seems that cast phenolic, usually (slightly incorrectly) called Bakelite, is now more fashionable and collectible than amber. It appears again and again at antiques fairs and in online auctions. The name is a contradiction in terms as it cannot be both amber and Bakelite, and, questioning the sellers, it becomes obvious that many of them do not know what they are selling but are throwing in extra names in order to sound good. Some sellers give guarantees that the material is real amber, while others describe dubious tests they have used to prove that the material is Bakelite. Other names used are 'Art Deco cherry amber red Bakelite', 'red amber Bakelite plastic', and various other combinations.
The beads -- usually necklaces -- fetch high prices, but it is now rumoured that many of them are in fact new and are not 'vintage'. There are a great number appearing for sale, and it is suspected that they are being produced to satisfy the market demand. It can be virtually impossible to tell a new one from a well-cared-for antique, so caution is needed.
Note: This article has previously been freely accessible and therefore continues to appear if 'Googled'. It is part of the organic gem materials archive called 'Organic Gems'. See www.maggiecp,com for more articles and information.