AMBER

AMBER,  is called the  "The Gold of the North"   -   Earliest-used gem material.   Unlike most gemstones, amber is technically not a mineral.  Minerals, by definition, are inorganic. Amber, on the other hand, is organic in origin - tree sap (resin of the pinus succinifera) that can be tens of millions of years old Specs.                             .  

Color: nearly colorless to white, light yellow to dark brown, red, green, black, blue.
Hardness: 2 - 2.5 Specific Gravity: 1.05 - 1.09 (max 1.30); will often float in super-saturated saline water. Cleavage: none. Fracture: conchoidal, brittle. Refractive Index: 1.54
Transparency: transparent to opaque. Chemical Composition: C₁₀H₁₆O (approx.)

First, one must understand that amber is the hardened  fossilized resin from ancient trees. In the Dominican Republic, the tree is Hyemnaea (a leguminous trees) Or  of a variety of coniferous and angiospermous trees.(Lundberg, 2000) The amber resin is so structurally sound, that it undergoes little change when it is buried in the earth. If the proper conditions for change exist on the earth, the resin then becomes amber. However, if the actual resin does not undergo that slight chemical change, the resin becomes copal. Due to its unique makeup, amber is able to stay embedded in the earth for millions of years. (Mashriq, 2000) The actual composition of amber is very complex. It is made up of four major elements, which give amber its unique characteristics. According to (Platt, 1999) the major elements involved are generally in this proportion: 67-87% Carbon, 15% Oxygen, 8.5-11% Hydrogen, and approximately .26% Sulphur.Although the specific makeup can vary in composition, this is what amber is most commonly formed of.

Amber actually relates to the resin that contains a chemical called succinic acid. (Platt, 1999)This chemical is written in the form COOH(CH2), which determines whether the amber is opaque or clear.Ý This characteristic variance is referred to as turbidity, which becomes a subdivision of its color. The lower the level of succinic acid in an amber resin, the clearer it will become.Ý If the amber resin is perfectly clear, it does not contain any percentage of succinic acid, and is referred to as retinite. Amber has an extremely low rating on the hardness scale. Most amber fossils stay around the 2 ranges, however, they vary in hardness from 1.5 to 2.5. (Amber, 2000) The younger the actual amber sample, the softer it tends to be. Even though amber's hardness is compared to that of talc and gypsum, it still tends to be tough. In addition to its toughness, amber's gravitational index is said to be as low as 1, and as high as 1.1.Ý This refers to the level of buoyancy that amber displays. In order for amber to be buoyant, it must be placed in highly salt saturated water.

An additional property of amber refers directly to its color and its fluorescence. Generally, the oxidized surface of amber creates an electric blue glow. The glowing capabilities of amber completely revolve around its color and the amount of Sulphur that is present in the sample. (Amber, 2000) If more blue and yellow tones are present in a sample of amber, its fluorescence increases.

Due to the fact that amber's fluorescent properties revolve around color, color is of importance. Amber varies in color greatly; its colors are as follows: clear, red, orange, yellow, blue, brown, white, and gray. As mentioned earlier, turbidity refers to the level of clarity of cloudiness that is evident in the amber. In addition to the level of succinic acid determining turbidity, the air bubbles within the amber also alter the level of clarity. Thousands of air bubbles are inside of each sample of amber, and they vary in size from .000017 mm to 02mm. (Platt, 1999) The closer together the air bubbles, the cloudier the amber sample becomes.

The inclusions within the amber, in addition to air bubbles and succinic acid, create turbidity. There are black inclusions, which are carbonized botanical items, such as wood, cones, and bark. (Amber, 2000) As well as black inclusions, there are thousands of insects and crustacean found within amber. The most common insect found is the fly, which accounts for almost 54% of the insects trapped in amber. Not only are animals and carbon-based inclusions found, but flowering plants, and spores are generally found as well. Some of the rare cases involved in amber fossils are the presence of reptiles, feathers, hair, and even actual bones. Trapped water has also been found within amber, and it eventually creates circular shapes inside the sample. The ability of light to bend and pass through amber is defined as its refractive index. This index is almost always at a level of 1.54, and is similar to that of a rock crystal. (Platt, 1999). The refractive index is a very important property because it causes the inclusions in amber, to become distorted. To counteract distortion, scientists must coat the amber in a fluid with a refractive index of 1.54

One fairly good way to determine fake amber is the 'hot point test'. This is where the fine point of a very hot needle is put in the amber. Real amber has a piney smell (or burnt resinous smell) and fake amber can have an electrical, plastic or sweet smell to it. The problem that you will have with this test is that most folks are not willing to sacrifice their potential prize piece of amber to this test.

Equally as bad is the burning test: amber burns with a black smoke, copal will burn with a whitish smoke, plastic immations can also burn with a black smoke. Again, who is willing to sacrifice their sample to this rather harsh test?

Another test is the acetone test. Acetone is the odoriferous chemical that is used to remove nail polish. Copal is slightly soluble (hasn't hardened enough over the millions of years) in acetone, so the surface will get sticky. Regular amber is not soluble and therefore acetone should not do anything to it. With plastic fakes, acetone can dissolve the outer layer, which can sometimes be a shellac coating. This is probably one of the easier tests.

For the geologists, amber has a refractive index of 1.5 to 1.6 (copal also is the same) while fakes of plastic and other chemicals will give a very different refractive index. The refractive index is a measure of how light is refracted when it goes through the amber. In order to do this test, you need a refractometer (a gemological instrument).

Amber is fluorescent. That is, when ultraviolet light (UV) is directed on the amber, it will fluoresce. Common fluorescent colors are yellow, blue, green and orange. The intensity of the fluorescence can be different with different types of amber. Dominican Republic amber usually fluoresces blue. This is a simple test if you happen to have a black light. Just shine the black light on the sample and observe the 'shine'.

Amber is not hard, when using the Moh's scale. It ranks usually from 2 to 2.5. Your fingernail is about 2 and thus it is very difficult to scratch amber. An American penny has a hardness of 3.0 and should scratch amber. Steel wool, which has a hardness of 5.5, when scraped on amber produces powder or very fine granules. If the piece is plastic, shavings will likely result.

Raw amber, when broken has conchodial fracture. That mean is looks similar to chipped glass. A chipped piece of glass will often show concentric circles in the chipped area. That is conchodial fracture. Amber does not have to chip in this fashion, but often will exhibit the type fracture cut.