CHERRY AMBER, REAL OR FAKE?
'Cherry amber' is the name given to much red material purporting to be amber. But is it?
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 is only found in Asia. How, then, can we find so much on the market today?
Many ambers look red if seen by transmitted light, that is, if light is shone through 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.
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.
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. A string of beads may be dragged down by the weight of the wet 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).
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.
Items sold as antique red amber carvings, which proved to be plastic imitations, and detail showing uneven surface dye.
Infra red spectroscopy tests can be performed in a laboratory that can distinguish between various ambers, and ambers and plastics, but few people have access to such tests. 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 by dubious and at best inconclusive, as dyes in the Bakelite can alter the test results. It is also potentially destructive.
CHERRY AMBER, REAL OR FAKE? -- UPDATE
Sherry Shatz, Certified Gemologist, SCC, author of 'What's It Made Of? A Jewelry Materials Identification Guide', sent a query about the even colour of plastic versus natural amber. The article states that even colour is an indication of plastic, while uneven colour is an indication of natural amber. There then follows an illustration of the uneven surface colour on plastic. This may have been confusing!
The surface colour on the amber fake illustrated is a dye which, in this case, has been applied to the surface of the item to make it appear red. Usually plastic items are dyed in manufacture, so that the colour is even right through the material. Natural Baltic amber is heat-treated to darken the surface and can appear red, but this is only skin deep and can be polished away. This tends to show up on facet edges where a final polish removes a little of the darkened surface. (See ‘Treatments and Enhancements of Baltic Amber’ in this issue, and ‘Cherry Amber, Real or Fake?’ in Issue 1.)
A new phenomenon has now reached the market, and was seen by the editor at the ‘Amberif’ amber fair in Poland in March. Red amber is now being processed in some way – some say thermal process, while others say pressed with pigments added – which results in totally transparent and completely evenly coloured amber, including red. There was no sign of paler facet edges or of impurities. The amber at the fair was facetted, had a high luster and was very pretty, but – in other surroundings -- it could have been mistaken for plastic. The editor was unable to discover the exact method used to produce the material, as it is a secret.
Red amber -- how was it treated? Section of Amber Room frame (left), and beads (right).
The material resembled 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. OG is still trying to find out.
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.