Amber is classed in various types: sea amber (found in the sea), pit amber (dug up, especially from the Baltic area), clear, massive, fancy, cloudy, frothy, fatty, and bone amber.
Highest values go those with clearly visible insects, light colors and clarity.
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
|Refractive Index||1.540 (+.005 -.001)|
|Colors||Yellow, brown, whitish yellow, reddish, cream color, orange shades. Rarely blue, greenish, violetish.|
|Hardness||2 - 2½|
|Specific Gravity||1.05 to 1.096, usually 1.08. (Air bubbles will lower SG.)|
|Density||1.05-1.096 (USUALLY ~1.08).|
|Cleavage||None. Fracture conchoidal.|
|Stone Sizes||The normal size of amber fragments is less than half a pound, but pieces weighing several pounds have been found. Amber is used often in making pipestems, as beads (tumble polished or faceted), pendants, earrings, and rings. It is also carved, sometimes ornately; used as inlay material, umbrella handles, and so forth.|
|Luminescence||Yellow in SW (Texas); bluish white or greenish in LW. Baltic amber may fluoresce grayish blue in SW. Insert in X-Rays. Sicilian amber is noted for its fluorescence.|
|Enhancements||Amber is darkened by heating. If done properly, this also creates the star spangles effects. Amber can also be dyed to darken the color.|
|Special Care Instructions||Avoid rough handling, heat and chemicals. Amber can be attacked, (partially dissolved,) by solvents, alcohol, etc.|
|Formula||Approximately C10H160 + H2S. A mixture of hydrocarbons, plus resins, succinic acid, and oils. Amber is the hardened resin of pine trees, sp. Pinus succinifera, age ~ 30 million years.|
OPTICS: R.I. ~1.54
OCCURRENCE: In sedimentary deposits and on shore-lines, due to the action of waves and currents in bringing material up from offshore beds.
East Prussia (now U.S.S.R.): Succinite
Entire Baltic Sea Region, including Poland, East Germany.
Norway, Denmark: also Romania and Sicily. Sicilian material may be opalescent blue or green.
Rarely found in England. Southern Mexico (Chiapas) produces golden yellow material.
Burma: brownish yellow and brown amber: also colorless, pale yellow, and orange.
Lebanon: scarce, from very old deposits.
Dominican Republic: mined from sedimentary rocks, yellow, orange, and red colors; this amber often contains well-preserved insects and sometimes displays a strong bluish tone in reflected light.
Cedar Lake, Manitoba, Canada.
Point Barrow, Alaska.
INCLUSIONS: Amber is noted for its inclusions, which are chiefly insects and pollen as well as leaves and other organic debris. These were trapped in the sticky fluid that oozed from pine trees millions of years ago and provide an intimate look at plant and insect life of that time period.
COMMENTS: Amber is classed in various types: sea amber (found in the sea), pit amber (dug up, especially from the Baltic area), clear, massive, fancy, cloudy, frothy, fatty, and bone amber.
Amber has been in use by humans for thousands of years, possibly longer than any other gem material. It is fairly common, easy to work with and a constant wonder to the eyes.
Amber is an amorphous mixture of organic compounds, including hydrocarbons, resins, succinic acid, and oils. Amorphous means that it has no crystalline structure. Organic refers to having its origin in living things.
It is commonly referred to as fossilized resin of ancient conifers. However, it is not a fossil in the common sense. Most fossils begin by having an animal or plant buried in the earth. Over a period of millennia, the organic material is slowly replaced with elements from the mineral kingdom.
Amber, on the other hand, has not had its organic elements replaced. Instead, the resin has gone through a chemical transformation. Amber has become a polymer, a natural plastic.
This gem comes in many colors, with the most common being yellow, orange and brown. Rarely, you will find amber with a green, blue, or violet tint. This is due to extreme fluorescence.
There are several shades of these colors and several grades of transparency. Jewelry is made almost exclusively from the transparent material. The opaque material is carved into a variety of artistic ornaments and useful utensils. Amber is also burned as incense and used as an ingredient in perfumes.
Amber is known for its inclusions. They consist of insects, pollen and plant debris from the time the tree was living. This offers a remarkable view into the past. In some of the finer specimens, whole termite colonies are trapped. They have chambers created with webbing. Some of the “rooms” are clearly nurseries, complete with egg sacks. Besides the termites, a variety of beetles, spiders, mites, and other insects can be in a single specimen.
Since the movie, “Jurassic Park,” the most popular insect inclusion is a mosquito. However, any clearly visible insect makes a piece highly valuable. Ancient plant material is of great interest to scientists, but of little value in the jewelry market. Most of it is in small pieces and not easily recognizable for what it is.
Another popular type of inclusion are “star spangles.” These internal fractures radiate from a central point. While quite attractive, most are human induced. Hence, they do not have the high value of a good quality insect.
Amber is often confused with copal. These are very similar materials, with nearly identical origins. The difference is that amber is millions of years old, copal just a few hundred thousand years old. There is also pressed amber, or ambroid, that is created by fusing smaller bits of amber under heat. You can distinguish this with a microscope..
Ancient techniques for identifying amber are still useful today. Rubbed vigorously on a piece of wool, it will generate a static charge, enough to pick up a small piece of ash. When it is warm enough, it also gives off a distinctive odor. These techniques will not distinguish amber from copal, but they will separate it from plastic imitations. (They are also great for entertaining inquisitive children.)
To distinguish between amber and copal is difficult. They share the same refractive index, specific gravity, and most other properties. Copal will fluoresce whiter than amber. That is a judgment call based on having a sufficient number of samples to recognize the difference. If you are not able to make the distinction based on fluorescence, you will have to resort to a destructive test.*
On an inconspicuous area, place a drop of acetone. Let it sit for three seconds, then wipe it off. Copal will have the surface damaged by the acetone. Amber will show little or no change from the brief exposure.
The easiest way to separate amber from its plastic imitations is with a specific gravity solution. A handy testing liquid can be made by boiling water and adding as much salt as you can dissolve in it. This will have a density of about 1.13. Amber, with a SG of 1.10 will float in this solution. Most of its imitations will sink.
A few plastics are have a density as low as 1.05 and many can be lower than amber if they have air bubbles inside. So, if your sample sinks, you can be sure it is not amber. If it floats you, need to determine if it is plastic or amber.
The RI will distinguish plastic if it varies from amber’s. However, since amber and plastic can both have an RI of 1.54, it will not tell you for certain if it is amber. Since they also share so many visual characteristics, you will probably have to use a hot point to distinguish them.
This is a destructive test, but with care, it can be done almost invisibly.* Find a place on your gem where a mark would be as unobtrusive as possible. This is usually on the bottom, an edge, or an area with existing scratches. Next, heat the tip of a needle until it glows red. Touch the selected spot just enough to release a tiny whiff of smoke.
Now for the hard part, smell the smoke. If it is amber, the smell is of fine incense. If it is chemical and offensive, it is plastic. This is another reason to make your test on as small a scale as possible!
* Destructive tests. Practice on your own material. Ask permission before using them on a customer’s gem.
Frequently seen in amber are flattened starburst shapes known as sun spangles. These are internal feathers and are caused by stress. Amber softens at about 150° C and melts at 250-300°C. Pressed amber; or ambroid, is made by melting small pieces of amber together under great pressure. This is usually detectable by careful microscopic investigation. Amber often darkens with age to a fine red-brown color. Pressed amber, however, may turn white with age.
Copal is a fossil resin of more recent origin than true amber. Prinicpal localities are South America, Africa, and New Zealand. Copals fluorescence whiter in SW-UV than amber and are easier to dissolve in solvents. Optical and physical properties are otherwise similar to amber. “Kauri Gum” is a copal from the kauri pine tree of New Zealand.
Amber is in great demand today, as it has been for centuries, and very large material is extremely rare, as are the more unusual colored varieties (blue, green). Good quality material is seldom used for anything but jewelry.
NAME: Arabic anbar, which the spanish converted to ambar, then later on Amber. Succinite is from succinum, the Latin word for amber, meaning juice.
by Dr. Joel Arem