The of the University of Hamburg has an extensive collection of Baltic amber with inclusions, although most is not open to the public. The Amber Working Group resides at the Geomatikum.
The University of Göttingen contains important parts of the earlier Königsberg (Kaliningrad) collection.
Greeks, Romans and antiquity: The Greek natural scientist, Aristotle, already knew of and reported on amber. Pytheas of Massilia is believed to have visited the Amber Islands (west, east, north Frisian Islands) around 334 v. Chr. The Romans, Tacitus and Plinius, wrote about amber, its origin and trade. Emperor Nero (54-68 n. Chr.) is said to have used amber for representation purposes in large quantities. The Romans opened the trade with Samland amber.
Amber can be ground wet using water resistant emery paper. Grits of 180, 400 and 1000 are recommended; only use rougher grain if much of the larger pieces shall be ground away. The amber should be washed off before each grit change. The amber surface in front of inclusions the amber surface should become as even as possible (glueing sandpaper with double stick adhesive tape on a disk). Fast motor driven grinding wheels can lead to heat damages of the amber, if there is no supply of water.
 
 

Hardness and weight: Amber is only little heavier than water (density around 1.07), thus sinks in fresh water, but floats in strongly salty water. The hardness varies between 2 and 3 (Mohs Hardness Scale) and is similar to hard plastic.
Healing powers: Particularly in earlier times amber was believed to possess welfare strength and it was helpful to breath the smoke from burning amber incense. Amber was powdered and prepared as an ointment; the oil distilled from amber was considered as a cure-all remedy, particularly against rheumatism. Duke Albrecht sent Martin Luther good amber for his 'bad' gallstone. Although amber remedies may not be effective, it is not injurious to health!
Hobby groups: A working group of amber collectors and researchers was founded at Hamburg, and at present led by Dr. Weitschat from the Geological-Paleontological Institute and Museum of the University of Hamburg. Topics include amber discovery locations, as well as research and determination of inclusions. The group is integrated in the promotion society of the institute and museum, meeting a few times in a year, with dues of 75.-DM. Membership is recommended for serious amber researchers to amber customers.
Hydraulic washing: In the amber open pit mining (e.g. in the Samland area) amber is floated, i.e. large quantities of water concentrate the amber when artificially washed. Even in Poland the amber is washed out hydraulically from deeper layers (often illegally) by means of floating drillings and then found at the surface.
 
 

During the Ice Ages (approximately 1,000,000 years ago, in the Pleistocene), enormous continental glaciations covered the Baltic Sea area at least six to eight times. The amber containing layers were planed off and most accumulations of Baltic amber were reworked again. The outwash sediment brought amber to northern Germany and Jutland, and even to northern Holland and eastern England.
Incense: Amber can be ignited easily with a lighter, contrary to synthetic resin, and this burning property was the origin of the German, brennstein, which means burning stone. The flame is brightly, reddish-brown and the burning amber smells like a pine resin. It flows together to form a black, inflexibly mass. In former times, amber was a popular incense, burnt to create an aromatic smoke.
The determination of amber inclusions is usually so difficult, identification should be left to specialists. Generally the arthropod evolution did not develop much since the Tertiary Period, so modern orders can be assigned and sometimes even families.
Inclusions of sea organisms: Contrary to some believers, there are no inclusions of sea organisms in amber. Naturally tracks and incrustations of modern sea organisms can be found on the surface of amber floating in the sea. Entombed organisms in amber are exclusively land inhabitants, usually of a Tertiary age, amber forest area. There are a very few fresh water inhabitant inclusions. The recently published is most likely a fantasy product.
 
 

"Inkluse" is a German technical term for an animal or plant inclusions in amber. The frequent pieces of decayed wood and stellate hairs in amber are normally not included with this term. Inclusions are often found in " Schlauben" and taps or stalactites.
Insects: including midges, gnats and flies, are the most frequent inclusions in Baltic amber. Only a few preserved midges and gnats in amber are found simultaneously with mosquitoes, which is an indirect sign of warm-blooded animals such as birds and mammals in the amber forest.
Jurassic and Triassic: From the older periods of the Middle Earth Ages (Triassic and Jurassic, of the Mesozoic, 220-140 million years) there are some places of discovery of fossil resins however, without important inclusions.
Kaffeedick, "Sprockholz": By water, amber is washed together with other materials, which have similar density, that is dark plant sections and small branches do not float on water. Depending upon the form, they are called cigars, "Sprockholz" (floating wood), or "Kaffeedick" (coffee grounds). One can search successfully in such shore-washed deposits in the Wadden Sea and along the coast.
 
 

"Knochen", or bone, is the German name of an amber type, which contains many microscopically small vesicles. The many bubbles cause the amber to look creamy white and contains no recognizable inclusions. It is preferable for making jewelry.
Lebanon amber, and amber found in the adjacent sections of Jordan and Israel, is some of the oldest amber types with inclusions, Lower Cretaceous, approximately 130 million years. Insect inclusions reveal the early developmental history of the amber. Bird feathers have been preserved.
Collections in Poland and Lithuania: The castle at , southeast from Gdansk (Danzig), Poland, was rebuilt after the war and has an important amber exhibition. Also the at Warsaw has an extensive amber department in its permanent collection. At Palanga, southern Lithuania, one of the most important can be found.
Mammals and reptiles: As a special feature a few bird feathers are preserved in Baltic amber. Hair or fur torn off mammals can also be found, and sometimes together with skin particles and even louse eggs. The hair identified to date has come from small rodents or bats. An alleged mammal jaw with teeth is perhaps more fantasy than true. inclusions are quite rare, and often falsified.
 
 

Mass catches are accumulations of amber with many inclusions. They show which small organisms ocurred under same conditions at the same place and perhaps important information (e.g. since the Baltic amber developed in quite different biotopes).
Open pit mining: For more than one century amber from the 'blue earth' is retrieved in open pit mining, near Palmnicken/Samland, today a part of Russia. The only open mining of amber in the German Federal Republic near Bitterfeldin Saxonia was closed in 1993.
Frequently mixtures of amber pieces and synthetic resin are offered for sale (e.g. at flea markets as amber). The cast-in amber pieces are easy to detect. Even now and then the amber pieces still contain inclusions!
The museum at Bad Füssing, Upper Bavaria, houses an dedicated to the amber's history of culture and crafts.
The Museum for Archeology and Ecology Dithmarschen at Albersdorf, Dithmarschen, Schleswig-Holstein has a small, but well explained collection of amber inclusions. A small amber collection can be seen at the , at Burg/Dithmarschen.
 
 

, a branch of the Museum of Natural History, has an cabinet with amber from all world. A special emphasis of the exhibition is Dominican amber with its animal and plant inclusions. It is worth seeing.
The name  amber" is often confused with ambra or ambergris, an aromatic mass expelled by sperm whales. The German name "Bernstein" means burning stone ("Brennstein"). The Greek amber name "electron" is still used as the word electricity. The Romans called amber succinum (" juice") because of a correct assumption that it developed from tree resin. Germanic people called it, according to the Roman author Pliny, glaes(um) or glass.
Needle test: With help of a glowing needle doubts can be eliminated as to whether it is amber or a plastic imitation. It melts and evaporates a tiny part of the surface of the piece which will be checked. The synthetic resin smell is different to the the resinous amber smell. It is best to test on an inferior amber piece!
 
 

North Sea amber is mostly Baltic amber, which was partially moved to the area of the North Sea coast prior to Ice Age rivers, by glaciation. Apart from the Wadden Sea shore, the sand banks near St.-Peter-Ording and the west coast of Jutland are most productive. North Danish amber might come from former amber forests of South Sweden, and this amber's origin is also referred to as west Baltic.
Oligocene is the name of the third of five sections of the Tertiary (35 - 26 million years). During the Oligocene, the sea penetrated into the Fennoscandic amber forest areas, eroded the lightweight amber and redeposited it in sandy deposits called "blue earth".
To perforate or drill the amber, one uses either a small drill, a drill with flexible wave, or a flywheel drill as used by goldsmiths. The drill should have its thickest place in front, so that it does not tilt. Twist drills must be used carefully, since they tilt easily and can break the amber.
Perforated with glowing needle: Some believe amber pieces could not be perforated prior to the Bronze Age, because of the need for a glowing metal needle. But that is possible only with very thin disks of amber, with quick and skillful workers. Amber was surely perforated with flint drills already during the Stone Age.
 
 

Plastics: Some amber types differ scarcely from plastics with similar colors. Sometimes it helps to grind a bit (amber smells resinous, but synthetic resin does not) or to prove authenticity by burning a bit, if necessary with a glowing needle. One must remember these are destructive tests and it is best to try these tests with inferior pieces of amber. Amber floats in concentrated saline solution, while synthetic resins usually sink.
Before polishing an amber piece, the surface should be ground with 600 or 1000 grit, until all of the scratches are gone. Amber is polished using a cloth or soft leather piece, and polishing paste (casting resin hobby accessories, although toothpaste will work). With moderate pressure, a fine, soft toothbrush and soap will eliminate the ugly paste remainders. Polishing materials should not come into contact with abrasive grit or dust!
Today most smaller pieces of amber are worked in polishing cylinders. These are hollow cylinders, filled with amber and a sharpening or polishing agents, turning slowly for weeks. Thus, the stones are polished all around, so that they only have to be drilled or perforated, to use them for making necklaces. Inclusions are relatively easy to recognize in amber from polishing cylinders, since only few pieces must be specially ground for this purpose.
Popular literature (in German) that introduces amber includes: Bismarck, R. v., Amber - Gold of the North, Neumünster (Wachholtz) 1987 (Touring Museum Kiel no. 3); Reinicke, R., Amber, Gold of the Sea. Rostock (Hinstorff) 1989; Schlee, D., Amber News, 1984; Schlee, D., The Amber Forest, 1986; Schlee, D., The Amber Cabinet, 1990. The booklets of Dieter Schlee are available from the society for the promotion of the Museum of Natural History at Stuttgart. Krummbiegel, Guenter and Brigitte: Amber, Fossil Resins from all World. Neustadt (Goldschneck Publishing house, fossil special issue 7) 1994 (Interesting, despite some mistakes in figure explanations, consider the correction supplement!). New and cheap: Manfred Kutscher, Bernstein (amber), Putbus/Rügen 1999, 64 pages, more than 150 (!) inclusion photos in colour. Available for 3.-DM (!!) + shipping at the society "Verein der Freunde und Förderer des Nationalparkes Jasmund e. V". , post box 34, D-18540 Sassnitz. See also specialist books.
Preservation: The cavities containing organisms and parts of organism included in the amber, are mostly filled with liquid or air, but can still contain organic remains such as chitin or muscle fibers. All larger animals and plant parts, which were incompletely covered by resin, had a poor chance for preservation. Some larger inclusions are difficult to recognize, because of reflecting fissures, and whitish coatings caused by humidity.
 
 

"Schlauben" is the German name of pieces of amber, which show layering boundaries. They developed when resin flowed in intervals and covered previous resin flows. Schlauben are mostly clear, sometimes milky, and often full of dirt and preserves most inclusions. This amber is not suitable for jewelry manufacture.
Sicilian amber, also called simetite, has been known since antiquity and is famous for its reddish color. It originates from the Upper Tertiary Period, is rare, and contains only a few inclusions.
"Sonnenflinten" are called natural fractures in clear amber, which can cause interesting mirror effects. Much "Sonnenflinten" are artificially produced today, termed "Blitzer" or sun spangles.
Specialist books: More special German literature featuring amber includes: Amber - Tears of the Gods, Essen (Glückauf) 1996/7, 585 pages. (This was an exhibition catalog of the German Mining Museum.) As a supplement to the exhibition catalog of the German Mining Museum a special edition of Metalla (66) was published in 1997, exclusively with amber topics. Both works contain extensive literature comments. The book of A. Bachofen-Echt, Amber and its Inclusions, Vienna 1949, came out again 1996 as a completed reproduction by J. Wunderlich publishing house, 75334 Straubenhardt. 1998 published: W. Weitschat and W. Wichard, Atlas of Plants and Animals in Baltic Amber, Munich (Dr. Friedrich Pfeil Publishing, 1998, in German), 128.-DM - the long-awaited manual!  - To my opinion, the best book specially for beginners is from Andrew Ross: Amber, the Natural Time Capsule, London (The Natural History Museum) 1998, with great identifying tables for amber inclusions and a lot of photos and drawings. Other Books in English: Grimaldi, David A., Amber - Window to the Past, New York (Harry N. Abrahams) 1998, 216 pages. Poinar, George O., Life in Amber, Palo Alto (Stanford University press) 1992. About Life in Dominican amber only: Poinar, George O. und Roberta, The Amber Forest, A Reconstruction of a Vanished World, Princeton University Press 1999. See also popular literature.
 
 

Spiders and mites are frequent inclusions in amber. The spiders might have often been attracted by the movement of the tiny animals sticking to the resin. Spider webs and even animals captured by the spider may be found. Mites next in abundance, after diptera, as the most frequent amber insect inclusions, are often overlooked as they are very small. Even parasitic mites dependent on birds are known.
Stalagtites or Taps (Germ. "Zapfen") developed from resin drops, which solidified before falling down. Renewed resin flows may transform them to thicker resin stalactites. Taps often contain inclusions, with the cores preserving inclusions of bits of branches. Drops have a typically flattened, roundish, bead form and maintain a natural decomposition crust.
Stellate hairs are the most frequent plant inclusions in Baltic and Bitterfeld amber. Those small tufts of hairs, not recognizable with the naked eye, are thought to be shelter hairs fallen from evergreen oaks, which grew in the 'amber forests.' Even if only one part of the amber contains such hairs it is an unmistakable, authentic character. Botanical remainders such as leaves, flowers and seed grains are comparatively rare in amber. More frequently are microscopic pollen grains.
Succinite is a technical mineralogical term for Baltic amber (after Latin "succinum" or juice). The composition and characteristics differentiate many amber types and fossil resins from succinite.
 
 

Termites and other inclusions: Tiny spring- tails (collembola) are frequent and as are small aphids, which can be easily overlooked. Occassionally caddis flies are found, whose larvae are dependent on water. Smaller representatives of various beetles are rarely observed, likewise larva stages of grasshoppers and cicadas. Among the rare inclusions are finds of termites, damselflies, eintagsfliegen, butterflies, pseudoscorpios and mantises. Attention grabbing inclusions include the few finds of fleas.
Tertiary Period: Most ambers and other fossil resins originate from the Tertiary Period (2-65 million years ago), including Baltic and North Sea amber. The Tertiary Period is also the age of mammal development.
Wasps: From the insect class of the Hymenoptera, ant workers and smallest wasps occur in Baltic amber most frequently. Braconid and chalcedonid wasps, deposit their eggs mostly into other insects (e.g. aphids) or even into their eggs, have a body length of only 1 mm.
Weather: Amber is occasionally found on sand beaches and in the dangerous floating ponds. Amber is found particularly after storms, amber becomes trapped where material was washed together and is somewhat heavier than water and does not float ('Sprockholz'). Along the Schleswig-Holstein west coast, the best finds are a few days after stormy weather abates.
 
 

• The Amber Dictionary from A-F
• Amber: A Perfect Fossil Trap
• The Living World in Amber (1)
• The Living World in Amber (2)
• The Micro World Embalmed in Amber
• Mysterious Unsolved Discoveries in Amber
• "Atlas of Plants and Animals in Baltic Amber"
• Amber Internet Links