Chemical composition of amber

Amber is hardened resin of historic and long extinct trees Pinus Succinifer. These trees belonged to pine class. The mineral can be white, yellow, greenish, azure, red, but most often found are shining in the sun, yellowish gold color formations. Because of this amber is often called the stone of the sun.

Amber is a compound of organic acids. It‘s chemical formula is C₁₀H₁₆O. Amber is composed out of several chemical elements. It contains 78% of carbon, around 11% of oxygen and around 10% of hydrogen. Sulphur impurities are frequent. Amber is soft, amorphic, doesn‘t have a correct crystal form, it‘s hardness according to Mohs scale – 2-2.5, sometimes increases up to 3, the density is from 1.05 to 1.096 g/cm³, so it‘s easily polished and buffed. By its classification class this mineral is attributed to burning mineral resources, humus carbon group.

According to O. Helm, amber has from 3 to 8 % of amber acid.

Opaque amber formations have less carbon than the clear pieces which can be evaluated as a compound of larger amounts of resin. Oxygen appears in amber in the form of bubbles, in the yellow clear amber up to 6000 bubbles in 1 сm³, in the opaque one – up 900 000. This means that the clarity of the stone is proportional to the amount of oxygen bubbles in it.

At a temperature of 150° C amber starts to soften and at 300° C it melts. It inflames easily and emits a smell of sap. This mineral is characterized by dielectric qualities and it contains heat. Naturally it‘s found in pieces with diameter from 1 to 10-20 cm or more, sometimes massive pieces weighing up to 10 kg can be found. The forms of the pieces are various: drops, droplets, irregular shaped formations, and porous plates, round shaped forms.

There are about 150 fossil (Latin fossilis – excavated) sorts of resin. From non-organic minerals fossil sap differ because they‘re made up of only three chemical elements: carbon, oxygen and hydrogen. During XVII – XVIII centuries when mining was on the rise, in brown carbon clusters first of all, later in other sediments various fossil sap sorts were found that varied greatly by their chemical characteristics. Most of the fossil sap was found in the Northern hemisphere, Europe and America during XX–XXI centuries. Also more and more of them are now found in Asia, Africa and South America.

Baltic amber is fossil Eocene period pine family coniferous tree resin that changed because of oxidation, polymerization, hydration and dehydration processes and the actions of microorganisms. An average composition of amber is: C – 78,55%, H – 9,64%, O – 11,81%. Amber started forming in the Cenozoic epoch Paleocene period around 55-40 million years ago. Coniferous trees, the so-called amber trees (Pinus succinifera), grew in the current regions of Scandinavia and close-by Baltic Sea bottom areas (The Baltic Sea started forming only 13 thousand year ago).

Amber is first mentioned in written sources in X century B.C. in Assyrian cuneiforms.

Amber pieces found are of various weights: from several grams to several kilograms.

Amber can be of various forms. It depends on the reljef on which it lay, on how the tree resin dripped.

Amber is very light, fragile, comparatively soft, so can easily be furbished. It difficultly transmits electrical current, but when rubbed to wooly materials gets electrified and maintains the electric charge for quite a while.

Amber‘s hardness according to Mohs scale varies between 2 and 3.

When irradiated by ultraviolet light amber shines in various colors (other similar materials don‘t have this quality).

According to color and clarity amber is divided into these sorts:

Clear amber – one of the most valued sorts. Is valued because of high clarity, beautiful yellow color of various intensity; sometimes in this sort you can find amber of water and ice color.

Flomic amber – a bit opaque, seems like dusty, with clear air holes, easily polished

Bastardic amber – moderately clear, with uneven yellow color and darker shadings, also easily polished.

Bone amber – opaque, unclear, very few shades, more similar to ivory than to amber, but is softer.

Foam amber – the furthest from amber if considering looks. Its color and structure reminds of stiffened foam – opaque, mealy; most porous, so the lightest of all (its lightness and softness can be felt by hand); this sort of amber is very difficult to furbish because of its porous nature, thus the article doesn‘t get the intensive shine. The clearer the amber, the denser and less porous it is, thus harder and with greater comparative weight.

Black, blue and green amber

Amber is also sorted according to its finding places:

Beckerite – (named according to the firm‘s ,,Stantien und Becker” owner) is found in round pieces like Shtantinite from the size of a cherry to a chicken‘s egg. The color is various brown shades. Opaque, porous, matt shininess, hard (Mohs scale – around 3), very tenacious, difficult to cut. Comparative weight around 1,26 g/cm. Components: C – 67,81%, H – 8,55%, O – 23,64%; has sulphur and comparatively much ash (up to 6%). Doesn‘t have amber acid. Practically doesn‘t melt in organic solvents.

Stantienite – (named according to the firm‘s ,,Stantien und Becker” owner) is found in small (up to 5cm) round, rugged surface, sometimes in rolls of layered structure, covered in matt black, shackled and fragile rot rind. Opaque, dark brown-black, with strong resin shine. Hardness – 32-36 kg/mm², comparative weight – 1,190 g/cm³. Components: C – 71,01%, H – 8,15% and O – 20,84%; has sulphur traces and ash (in the tainted samples). Doesn‘t have amber acid. Almost doesn‘t dissolve in solvents. Stantienite has a comparatively large amount of calcium.

Krancite – (named after doctor Kranc) isn‘t found in amber clusters. It is flushed out by the Baltic Sea around Prust horn, in Semba, sometimes in other places. Found in very small (1-2cm) pieces, partially clear and clear, in greenish yellowish pieces covered in think brownish red or rosy grey and fragile rot rind, in fresh breakage with the shininess of grease. Its comparative weight is less than one. Differs from other fossil resin by its softness and elasticity. Components: C – 78,38%, H – 10,4%, O – 11,48 and has some ash. Amber acid isn‘t present. Doesn‘t dissolve in organic solvents, only swells in some. When heated at 100°C temperature becomes fragile, melts only at 300°C at totally disintegrates.

Gedanite – (from the Latin name of Gdansk Gedanum) is found 1-2 cm size, more rarely the size of the fist, in round and uneven form lumps. Reminds of rosin by its looks: clear, rarely a bit cloudy, palely yellow, with bright glassy shine. The surface of the pieces is mat, whitish, seems like covered in flour. Hardness according to Mohs scale – 1.5-2 which means fragile. Comparative weight is  1,110 g/cm³. Melts in the interval of 140-340°C temperatures, foams a lot, and eventually totally disintegrates. Composition: C – 81,01%, H – 11,41%, O – 7,33%, has sulphur and ash traces, but only in tainted samples.

Glesite – (from the historic German name of amber „glesum“) is found in small 1-5 cm round pieces. Usually unclear, sometimes a bit transparent, reddish brown and black color, with greasy shine. Most of the times covered in 1-3 mm thick light, sometimes even white, changed material rugged surface coating. Comparative weight is ,207 g/cm³, hardness in Mohs scale around 2. Fragility is low, much worse than of amber. Melts at 290°C, but from 120°C starts to swell, soften and at 200°C becomes a  sticky liquid. Components: C – 79,36%, H – 9,48%, O – 10,72%, around 0,5% sulphur is found and traces of amber acid. Differs greatly from other fossil sap by IR specter.

Because of trivial physical and chemical differences in characteristics, various resins from different founding places were called differently: Moravian (Slovakia) resin – Valchovite, South Polish and Slovakian – Noidorfite, Men and Luar resin – Copalite and so on. We can attribute Telefolite to this group. All of these strains are of very various colors and shades – from light to dark red and brown, of various clarity – from totally clear to opaque. The clarity depends only on the impurities of the resin. Their comparative weight is very similar (1,04-1,05 g/cm), hardness – from 2 to 2.5 according to Mohs scale. All of them are very fragile and similar to Gedanite. Composition: C – 79,2-80,4%, H – 9,6-11,0%, O – 7,3-11,2%. Some sorts have a lot of sulphur (up to 4%) and emit hydrogen sulphite gas when melted. The amount of ash depends on the level of impurity. In organic solvents they melt differently, though quite well.

Rumenite – is found in Carpathian region, especially Romania. Most of it is found in the river Buzej basin, various sized pieces (sometimes 1-2 kg). Usually opaque, brown yellow and dark red, rarely light yellow. Tenacious, hardness – 2.3-3 according to Mohs scale, comparative weight –  1,06-1,1 g/cm³. Components: C – 80,3%, H – 10,2%, O-8,3%,has around 1.5% sulphur and quite a lot of amber acid (for ex., some have up to 5%). Dissolving is low, dissolves in alcohol only around 6%. Melts at 350-370°C temperature. Together with Rumenite in the Ploesch region at its bituminous sandstone an original fossil sort of resin is found called piatra. It‘s very shuck, greenish blue, dark green and brownish green colored fluorescent resin that is a bit harder than rumenite. It has little oxygen, around 2.5-3%. In the river Almash basin black, glass shiny bituminous resin is found with a chemical composition similar to piatra, but a bit ashier. This resin is called almashite.

Around Olanesch region light yellow, sometimes brownish, quite clear sap is found that‘s covered in sticky bitumen. They‘re attributed to Copalites. Like piatra it‘s characterized by low oxygen amount – around 2.5%. Dissolves well in solvents, dissolves completely in chloroform. In Moldova in the basin of river Bukovina quite often opaque resin of hyacinth color is found. It‘s attributed to Shraufite. It‘s found in quite large pieces (10-20 cm). Characterized by large amount of oxygen (around 17%), quite good dissolvent and high (320-350°C) melting temperature.

In the surroundings of Deliatin the great lumps of deliatinite are found which is very close to the Baltic amber by its characteristics and composition (has around 0,8-1,7% of amber acid).

In Sicily, at the basin of Simet river and in North Italy clear dark red and yellow, sometimes blue, green or grey fossil sap is found with fluorescent color. They‘re called Simetite. The hardness is 2-2,5 by Moss scale, comparative weight – 1,05-1,06 g/cm³. Components: C – 68,5%, H – 9,4%, O – 21,3%. Lots of sulphur and up to 0.2% of amber acid is found in them. Dissolves quite well in ether and alcohol, melts at 350 -370°C temperatures.

Apart from the mentioned ones, many fossil resin found in Europe and characterized by various qualities are attributed to amber. For example, wax-like opaque dark brown duksite found in Bohemia‘s brown coal.

In Styria, Austria, also in the brown coal clusters, keflachite is found which is heated even at 25°C temperatures and becomes sticky, at 80°C degrees – soft, and at 98°C – melts.

In Oberhart, Austria hyacinth red iksolite is found that melts at 100°C temperature.

Light yellow jaulingite is found in Lower Austria. Both these resin types melt in low temperatures and dissolve very well in organic solvents as well as disintegrate in air becoming whitish-yellowish dust.

Kiscelite that is found near Budapest and is of organic fossil nature is also considered to be amber. Kiscelite is yellow and brownish green, fragile and has up to 4% sulphur. When heated it emits a lot of hydrogen sulfide gas. By their chemical qualities two other natural materials differ from fossil sap, especially from the Baltic amber.

One of them is know by the name of euosmite and is found in Bajershof brown coal cluster in Bavaria. It‘s brownish yellow, opaque, not very hard (hardness by Mohs scale – 1.5), with high comparative weight (1,2-1,5 g/cm³) and with strong camphor or Rosemarie smell. It totally dissolves even in cold alcohol and ether, melts at 77°C temperature.

The second material is zigburite found in the brown coal mine layer around Bona. It‘s gold yellow and hyacinth red (to brown) color, with a glassy shine. Fragile (hardness – 2-2,5 according to Mohs scale), is differentiated by a unique composition: C – 81,4%,  H – 5,3%, O – 13,3%.

Lots of fossil resins finding places are located in North Siberia, especially Jugor and Taimyr peninsulas. Since the old days they‘re known as Siberian retinites. This resin is found in small (from few millimeters to 5 cm) pieces, they‘re not very hard, but very fragile, reminds of gedanite by its looks and qualities. Composition: C – 80,83%, H – 11,6%, O – 7,07%,, has traces of sulphur.

The oldest know Asian fossil resin is found in Burma, at the source of Iravadi River. Since XVIII century it was known in China and other Buddhist countries by the name Fupo and now it‘s called birmite. It‘s mostly opaque, dark brown, rarely red or even yellow resin. They‘re found quite big (even up to human head sizes). Hardness – around 2.5-3 by Mohs scale, comparative weight – from 1,03 to 1,09 g/cm³. Composition: C – 80%, H – 11,5%, O – 8,4%, has traces of sulphur and ash. It‘s tenacious. No amber acid is present. Difficultly dissolves in all solvents, when melted totally disintegrates.

Fossil sap close to the Siberian Retinite is also found in North America, Alaska. It‘s possible that amber called siderite (or chemavinite) is relative to it. It‘s found on the shores of  Sidar lake and all river Saskacevan basin. It‘s very close to retinites by the element composition.

Fossil resin is also found in Mexico, Ciapo state, Yucatan peninsula, Haiti and other places. It‘s known as Mexican amber. It‘s characterized by clarity, golden yellow and yellowish red color and beautiful fluorescence. More fossil resin is found in America can is very close to the Baltic amber by its qualities. In South Carolina, around Charlestown ambrozine is found and on the Southern-most part of Chile, near Magellan’s channel, the so-called Chilean sukcinite is found.

The first one has a lot of amber acid and the second one externally looks very similar to amber, it‘s elemental composition and qualities are also similar.

Probably the most interesting are blue and green amber found in Dominican island.

Amber acid, oil, glaze, rosin, medicine, paint and other various materials can be manufactured from amber.

Amber acid НООС-СН₂-СН₂-СООН can be found not only in amber, but other plants as well. It stimulates growth and increases productivity. Amber acid is used when preparing medicines, rosins, plastic, in analytical chemistry and synthesis.