Amber is a treeresinfossil. Examples of it have been appreciated for its color and natural beauty since theNeolithic times,[1] and worked as agemstone since antiquity.[2] Amber is used injewelry and as a healing agent infolk medicine.
There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material asinclusions.[3] Amber occurring in coal seams is also calledresinite, and the termambrite is applied to that found specifically within New Zealand coal seams.[4]
The English wordamber derives fromArabicʿanbarعنبر[5] viaMiddle Latinambar andMiddle Frenchambre. The word referred to what is now known asambergris (ambre gris or "gray amber"), a solid waxy substance derived from thesperm whale. The word, in its sense of "ambergris," was adopted inMiddle English in the 14th century.[6]
In theRomance languages, the sense of the word was extended toBaltic amber (fossil resin) from as early as the late 13th century.[7] At first called white or yellow amber (ambre jaune), this meaning was adopted in English by the early 15th century. As the use of ambergris waned, this became the main sense of the word.[5][better source needed]
The two substances ("yellow amber" and "gray amber") conceivably became associated or confused because they both were found washed up on beaches. Ambergris is less dense than water and floats, whereas amber is denser and floats only in concentrated saline, or strong salty seawater though less dense than stone.[8]
The classical names for amber,Ancient Greekἤλεκτρον (ēlektron) and one of itsLatin names,electrum,[a] are connected to a term ἠλέκτωρ (ēlektōr) meaning "beaming Sun".[10][11] According to myth, whenPhaëton, son ofHelios (the Sun) was killed, his mourning sisters becamepoplar trees, and their tears becameelektron, amber.[12] The wordelektron gave rise to the wordselectric, electricity, and their relatives because of amber's ability to bear a charge ofstatic electricity.[13]
A number of regional and varietal names have been applied to ambers over the centuries, includingAllingite,Beckerite,Gedanite,Kochenite,Krantzite, andStantienite.[14]
Pytheas says that theGutones, a people of Germany, inhabit the shores of an estuary of the Ocean called Mentonomon, their territory extending a distance of six thousand stadia; that, at one day's sail from this territory, is the Isle ofAbalus, upon the shores of which, amber is thrown up by the waves in spring, it being an excretion of the sea in a concrete form; as, also, that the inhabitants use this amber by way of fuel, and sell it to their neighbors, theTeutones.
Fishing for amber on the coast of Baltic Sea. Winter storms throw out amber nuggets. Close to Gdańsk, Poland.
Earlier Pliny says that Pytheas refers to a large island—three days' sail from theScythian coast and calledBalcia byXenophon of Lampsacus (author of a fanciful travel book in Greek)—asBasilia—a name generally equated withAbalus.[16] Given the presence of amber, the island could have beenHeligoland,Zealand, the shores ofGdańsk Bay, theSambia Peninsula or theCuronian Lagoon, which were historically the richest sources of amber in northern Europe.[citation needed] There were well-established trade routes for amber connecting the Baltic with the Mediterranean (known as the "Amber Road"). Pliny states explicitly that the Germans exported amber toPannonia, from where theVeneti distributed it onwards.
The ancient Italic peoples of southern Italy used to work amber; the National Archaeological Museum of Siritide (Museo Archeologico Nazionale della Siritide) atPolicoro in theprovince of Matera (Basilicata) displays important surviving examples. It has been suggested that amber used in antiquity, as atMycenae and in the prehistory of the Mediterranean, came from deposits inSicily.[17]
Amber is produced from a marrow discharged by trees belonging to the pine genus, like gum from the cherry, and resin from the ordinary pine. It is a liquid at first, which issues forth in considerable quantities, and is gradually hardened [...] Our forefathers, too, were of opinion that it is the juice of a tree, and for this reason gave it the name of "succinum" and one great proof that it is the produce of a tree of the pine genus, is the fact that it emits a pine-like smell when rubbed, and that it burns, when ignited, with the odour and appearance of torch-pine wood.[19]
He also states that amber is also found in Egypt and India, and he even refers to theelectrostatic properties of amber, by saying that "in Syria the women make thewhorls of their spindles of this substance, and give it the name ofharpax [from ἁρπάζω, "to drag"] from the circumstance that it attracts leaves towards it, chaff, and the light fringe of tissues".
The Romans traded for amber from the shores of the southernBaltic at least as far back as the time ofNero.[20]
Amber has a long history of use in China, with the first written record from 200 BCE.[21] Early in the 19th century, the first reports of amber found in North America came from discoveries inNew Jersey alongCrosswicks Creek nearTrenton, atCamden, and nearWoodbury.[2]
Most amber has a hardness between 2.0 and 2.5 on theMohs scale, arefractive index of 1.5–1.6, aspecific gravity between 1.06 and 1.10, and a melting point of 250–300 °C.[26] Heated above 200 °C (392 °F), amber decomposes, yielding anoil of amber, and leaves a black residue which is known as "amber colophony", or "amber pitch"; when dissolved in oil ofturpentine or inlinseed oil this forms "amber varnish" or "amber lac".[23]
Molecular polymerization,[22] resulting from high pressures and temperatures produced by overlying sediment, transforms the resin first intocopal. Sustained heat and pressure drives offterpenes and results in the formation of amber.[27] For this to happen, the resin must be resistant to decay. Many trees produce resin, but in the majority of cases this deposit is broken down by physical and biological processes. Exposure to sunlight, rain, microorganisms, and extreme temperatures tends to disintegrate the resin. For the resin to survive long enough to become amber, it must be resistant to such forces or be produced under conditions that exclude them.[28] Fossil resins from Europe fall into two categories, the Baltic ambers and another that resembles theAgathis group. Fossil resins from the Americas and Africa are closely related to the modern genusHymenaea,[29] while Baltic ambers are thought to be fossil resins from plants of the familySciadopityaceae that once lived in north Europe.[30]
Baltic amber with inclusions
The abnormal development of resin in living trees (succinosis) can result in the formation of amber.[31] Impurities are quite often present, especially when the resin has dropped onto the ground, so the material may be useless except for varnish-making. Such impure amber is calledfirniss.[32] Suchinclusion of other substances can cause the amber to have an unexpected color.Pyrites may give a bluish color.Bony amber owes its cloudy opacity to numerous tiny bubbles inside the resin.[33] However, so-calledblack amber is really a kind ofjet.[34] In darkly clouded and even opaque amber, inclusions can be imaged using high-energy, high-contrast, high-resolutionX-rays.[35]
Open cast amber mine "Primorskoje" in Jantarny, Kaliningrad Oblast, RussiaExtracting Baltic amber from Holocene deposits, Gdańsk, Poland
Amber is globally distributed in or around all continents,[36] mainly in rocks ofCretaceous age or younger. Historically, the coast west ofKönigsberg inPrussia was the world's leading source of amber. The first mentions of amber deposits there date back to the 12th century.[37]Juodkrantė inLithuania was established in the mid-19th century as a mining town of amber. About 90% of the world's extractable amber is still located in that area, which was transferred to theRussian Soviet Federative Socialist Republic of theUSSR in 1946, becoming theKaliningrad Oblast.[38]
Pieces of amber torn from the seafloor are cast up by the waves and collected by hand, dredging, or diving. Elsewhere, amber is mined, both in open works and underground galleries. Then nodules ofblue earth have to be removed and an opaque crust must be cleaned off, which can be done in revolving barrels containing sand and water. Erosion removes this crust from sea-worn amber.[33]Dominican amber is mined throughbell pitting, which is dangerous because of the risk of tunnel collapse.[39]
An important source of amber isKachin State in northernMyanmar, which has been a major source of amber in China for at least 1,800 years. Contemporary mining of this deposit has attracted attention for unsafe working conditions and its role in fundinginternal conflict in the country.[40] Amber from theRivne Oblast of Ukraine, referred to asRivne amber, is mined illegally by organised crime groups, who deforest the surrounding areas and pump water into the sediments to extract the amber, causing severe environmental deterioration.[41]
The Vienna amber factories, which use pale amber to manufacture pipes and other smoking tools, turn it on alathe and polish it with whitening and water or withrotten stone and oil. The final luster is given by polishing with flannel.[33]
When gradually heated in an oil bath, amber "becomes soft and flexible. Two pieces of amber may be united by smearing the surfaces with linseed oil, heating them, and then pressing them together while hot. Cloudy amber may be clarified in an oil bath, as the oil fills the numerous pores that cause the turbidity. Small fragments, formerly thrown away or used only for varnish are now used on a large scale in the formation of "ambroid" or "pressed amber".[33] The pieces are carefully heated with exclusion of air and then compressed into a uniform mass by intense hydraulic pressure, the softened amber being forced through holes in a metal plate. The product is extensively used for the production of cheap jewelry and articles for smoking. This pressed amber yields brilliant interference colors in polarized light."[42]
Amber has often been imitated by other resins likecopal andkauri gum, as well as bycelluloid and even glass. Baltic amber is sometimes colored artificially but also called "true amber".[33]
Amber occurs in a range of different colors. As well as the usual yellow-orange-brown that is associated with the color "amber", amber can range from a whitish color through a pale lemon yellow, to brown and almost black. Other uncommon colors include red amber (sometimes known as "cherry amber"), green amber, and evenblue amber, which is rare and highly sought after.[43]
Yellow amber is a hard fossil resin from evergreen trees, and despite the name it can be translucent, yellow, orange, or brown colored. Known to the Iranians by the Pahlavi compound word kah-ruba (fromkah "straw" plusrubay "attract, snatch", referring to its electrical properties[13]), which entered Arabic as kahraba' or kahraba (which later became the Arabic word forelectricity, كهرباءkahrabā'), it too was called amber in Europe (Old French and Middle English ambre). Found along the southern shore of the Baltic Sea, yellow amber reached the Middle East and western Europe via trade. Its coastal acquisition may have been one reason yellow amber came to be designated by the same term as ambergris. Moreover, like ambergris, the resin could be burned as an incense. The resin's most popular use was, however, for ornamentation—easily cut and polished, it could be transformed into beautiful jewelry. Much of the most highly prized amber is transparent, in contrast to the very common cloudy amber and opaque amber. Opaque amber contains numerous minute bubbles. This kind of amber is known as "bony amber".[44]
Although all Dominican amber is fluorescent, the rarest Dominican amber is blue amber. It turns blue in natural sunlight and any other partially or whollyultraviolet light source. In long-wave UV light it has a very strong reflection, almost white. Only about 100 kg (220 lb) is found per year, which makes it valuable and expensive.[45]
Sometimes amber retains the form of drops andstalactites, just as it exuded from the ducts and receptacles of the injured trees.[33] It is thought that, in addition to exuding onto the surface of the tree, amber resin also originally flowed into hollow cavities or cracks within trees, thereby leading to the development of large lumps of amber of irregular form.
Amber can be classified into several forms. Most fundamentally, there are two types of plant resin with the potential for fossilization.Terpenoids, produced byconifers andangiosperms, consist of ring structures formed ofisoprene (C5H8) units.[1]Phenolic resins are today only produced by angiosperms, and tend to serve functional uses. The extinctmedullosans produced a third type of resin, which is often found as amber within their veins.[1] The composition of resins is highly variable; each species produces a unique blend of chemicals which can be identified by the use ofpyrolysis–gas chromatography–mass spectrometry.[1] The overall chemical and structural composition is used to divide ambers into five classes.[46][47] There is also a separate classification of amber gemstones, according to the way of production.[citation needed]
This class is by far the most abundant. It comprises labdatriene carboxylic acids such as communic orozic acids.[46] It is further split into three sub-classes. Classes Ia and Ib utilize regular labdanoid diterpenes (e.g. communic acid, communol, biformenes), while Ic usesenantio labdanoids (ozic acid, ozol,enantio biformenes).[48]
Class Ia includesSuccinite (= 'normal' Baltic amber) andGlessite.[47] They have a communic acid base, and they also include much succinic acid.[46]Baltic amber yields on dry distillation succinic acid, the proportion varying from about 3% to 8%, and being greatest in the pale opaque orbony varieties. The aromatic and irritating fumes emitted by burning amber are mainly from this acid. Baltic amber is distinguished by its yield ofsuccinic acid, hence the namesuccinite. Succinite has a hardness between 2 and 3, which is greater than many other fossil resins. Its specific gravity varies from 1.05 to 1.10.[23] It can be distinguished from other ambers viainfrared spectroscopy through a specificcarbonyl absorption peak. Infrared spectroscopy can detect the relative age of an amber sample. Succinic acid may not be an original component of amber but rather a degradation product ofabietic acid.[49]
Class Ib ambers are based on communic acid; however, they lack succinic acid.[46]
Class Ic is mainly based onenantio-labdatrienonic acids, such as ozic and zanzibaric acids.[46] Its most familiar representative is Dominican amber,.[1] which is mostly transparent and often contains a higher number of fossil inclusions. This has enabled the detailed reconstruction of the ecosystem of a long-vanished tropical forest.[50] Resin from the extinct speciesHymenaea protera is the source of Dominican amber and probably of most amber found in the tropics. It is not "succinite" but "retinite".[51]
Class V resins are considered to be produced by a pine or pine relative. They comprise a mixture of diterpinoid resins andn-alkyl compounds. Their main variety isHighgate copalite.[47]
Typical amber specimen with a number of indistinct inclusions
The oldest amber recovered dates to thelate Carboniferous period (320 million years ago).[1][52] Its chemical composition makes it difficult to match the amber to its producers – it is most similar to the resins produced by flowering plants; however, the first flowering plants appeared in the Early Cretaceous, about 200 million years after the oldest amber known to date, and they were not common until theLate Cretaceous. Amber becomes abundant long after the Carboniferous, in theEarly Cretaceous,[1] when it is found in association with insects. The oldest amber with arthropod inclusions comes from theLate Triassic (lateCarnianc. 230 Ma) of Italy, where four microscopic (0.2–0.1 mm) mites,Triasacarus,Ampezzoa,Minyacarus andCheirolepidoptus, and a poorly preservednematoceran fly were found in millimetre-sized droplets of amber.[53][54] The oldest amber with significant numbers of arthropod inclusions comes from Lebanon. This amber, referred to asLebanese amber, is roughly 125–135 million years old, is considered of high scientific value, providing evidence of some of the oldest sampled ecosystems.[55]
In Lebanon, more than 450 outcrops of Lower Cretaceous amber were discovered by Dany Azar,[56] a Lebanese paleontologist and entomologist. Among these outcrops, 20 have yielded biological inclusions comprising the oldest representatives of several recent families of terrestrial arthropods. Even olderJurassic amber has been found recently in Lebanon as well. Many remarkable insects and spiders were recently discovered in the amber of Jordan including the oldestzorapterans,clerid beetles,umenocoleidroaches, and achiliidplanthoppers.[55]
A snail and a few insects trapped within Burmese amber
Burmese amber from theHukawng Valley in northern Myanmar is the only commercially exploited Cretaceous amber.Uranium–lead dating ofzircon crystals associated with the deposit have given an estimated depositional age of approximately 99 million years ago. Over 1,300 species have been described from the amber, with over 300 in 2019 alone.
Baltic amber is found as irregularnodules in marineglauconitic sand, known asblue earth, occurring in Upper Eocene strata ofSambia in Prussia.[23] It appears to have been partly derived from olderEocene deposits and it occurs also as a derivative phase in later formations, such asglacial drift. Relics of an abundant flora occur as inclusions trapped within the amber while the resin was yet fresh, suggesting relations with the flora of eastern Asia and the southern part of North America.Heinrich Göppert named the common amber-yielding pine of the Baltic forestsPinites succiniter, but as the wood does not seem to differ from that of the existing genus it has been also calledPinus succinifera. It is improbable that the production of amber was limited to a single species; and indeed a large number of conifers belonging to different genera are represented in the amber-flora.[33]
Amber is a unique preservational mode, preserving otherwise unfossilizable parts of organisms; as such it is helpful in the reconstruction of ecosystems as well as organisms;[57] the chemical composition of the resin, however, is of limited utility in reconstructing the phylogenetic affinity of the resin producer.[1] Amber sometimes contains animals or plant matter that became caught in the resin as it was secreted.Insects,spiders and even their webs,annelids,frogs,[58]crustaceans,bacteria andamoebae,[59] marine microfossils,[60] wood, flowers and fruit, hair, feathers[3] and other small organisms have been recovered in Cretaceous ambers (deposited c.130 million years ago).[1] There is even anammonitePuzosia (Bhimaites) and marinegastropods found inBurmese amber.[61]
The preservation of prehistoric organisms in amber forms a key plot point inMichael Crichton's 1990 novelJurassic Park and the1993 movie adaptation bySteven Spielberg.[62] In the story, scientists are able to extract the preserved blood ofdinosaurs from prehistoricmosquitoes trapped in amber, from which they genetically clone living dinosaurs. Scientifically this is as yet impossible, since no amber with fossilized mosquitoes has ever yielded preserved blood.[63] Amber is, however, conducive to preservingDNA, since it dehydrates and thus stabilizes organisms trapped inside. One projection in 1999 estimated that DNA trapped in amber could last up to 100 million years, far beyond most estimates of around 1 million years in the most ideal conditions,[64] although a later 2013 study was unable to extract DNA from insects trapped in much more recentHolocenecopal.[65] In 1938, 12-year-oldDavid Attenborough (brother ofRichard who played John Hammond inJurassic Park) was given a piece of amber containing prehistoric creatures from his adoptive sister; it would be the focus of his 2004 BBC documentaryThe Amber Time Machine.[66]
Pendants made of amber. The ovalpendant is 52 by 32 mm (2 by1+1⁄4 in).Amber necklace from 2000 to 1000 BCE
Amber has been used as jewelry since theStone Age, from 13,000 years ago.[1] Amber ornaments have been found in Mycenaean tombs and elsewhere across Europe.[67] To this day it is used in the manufacture of smoking and glassblowing mouthpieces.[68][69] Amber's place in culture and tradition lends it a tourism value;Palanga Amber Museum is dedicated to the fossilized resin.[70]
Amber has long been used in folk medicine for its purported healing properties.[71] Amber and extracts were used from the time ofHippocrates in ancientGreece for a wide variety of treatments through the Middle Ages and up until the early twentieth century.[72]
Amber necklaces are a traditional European remedy forcolic orteething pain with purported analgesic properties of succinic acid, although there is no evidence that this is an effective remedy or delivery method.[71][73][74] TheAmerican Academy of Pediatrics and theFDA have warned strongly against their use, as they present both a choking and a strangulation hazard.[73][75]
Inancient China, it was customary to burn amber during large festivities. If amber is heated under the right conditions, oil of amber is produced, and in past times this was combined carefully withnitric acid to create "artificial musk" – a resin with a peculiarmusky odor.[76] Although when burned, amber does give off a characteristic "pinewood" fragrance, modern products, such asperfume, do not normally use actual amber because fossilized amber produces very little scent. In perfumery, scents referred to as "amber" are often created and patented[77][78] to emulate the opulent golden warmth of the fossil.[79]
The scent of amber was originally derived from emulating the scent ofambergris and/or the plant resinlabdanum, but since sperm whales are endangered, the scent of amber is now largely derived from labdanum.[80] The term "amber" is loosely used to describe a scent that is warm, musky, rich and honey-like, and also somewhat earthy.Benzoin is usually part of the recipe.Vanilla andcloves are sometimes used to enhance the aroma. "Amber" perfumes may be created using combinations of labdanum, benzoin resin, copal (a type of tree resin used in incense manufacture), vanilla,Dammara resin and/or synthetic materials.[76]
Epoxynovolac (phenolic resins), unofficial name "antique amber", not in the use at present
Polyesters (Polish amber imitation) withstyrene. For example, unsaturated polyester resins (polymals) are produced by Chemical Industrial Works "Organika" inSarzyna,Poland; estomal are produced byLaminopol firm. Polybern or sticked amber is artificial resins the curled chips are obtained, whereas in the case of amber – small scraps. "African amber" (polyester, synacryl is then probably other name of the same resine) are produced by Reichhold firm; Styresol trade mark or alkid resin (used in Russia, Reichhold, Inc. patent, 1948.[87]
^"Amber". (1999). In G. W. Bowersock, Peter Brown, Oleg Grabar (eds.)Late Antiquity: A Guide to the Postclassical World, Harvard University Press,ISBN0674511735.
^Anderson, Ken B. (1996). "New Evidence Concerning the Structure, Composition, and Maturation of Class I (Polylabdanoid) Resinites".Amber, Resinite, and Fossil Resins. ACS Symposium Series. Vol. 617. pp. 105–129.doi:10.1021/bk-1995-0617.ch006.ISBN978-0-8412-3336-2.
^abPoinar, P.O., Jr., and R.K. Milki (2001)Lebanese Amber: The Oldest Insect Ecosystem in Fossilized Resin. Oregon State University Press, Corvallis.ISBN0-87071-533-X.
^Azar, Dany (2012). "Lebanese amber: a "Guinness Book of Records"".Annales Universitatis Paedagogicae Cracoviensis.111:44–60.
^J.L. Bada, X.S. Wang, H. Hamilton (1999). "Preservation of key biomolecules in the fossil record: Current knowledge and future challenges". Philos Trans R Soc Lond B Vol. 354. pp. 77–87.{{cite news}}: CS1 maint: multiple names: authors list (link)
^Riddle, John M. (1973). "AMBER in ancient Pharmacy: The Transmission of Information About a Single Drug: A Case Study".Pharmacy in History.15 (1):3–17.
^Perfume compositions and perfume articles containing one isomer of an octahydrotetramethyl acetonaphthone, John B. Hall, Rumson; James Milton Sanders, EatontownU.S. patent 3,929,677, Publication Date: 30 December 1975
This article incorporates text from a publication now in thepublic domain: Rudler, Frederick William (1911). "Amber". InChisholm, Hugh (ed.).Encyclopædia Britannica. Vol. 1 (11th ed.). Cambridge University Press. pp. 792–794.
Bogdasarov, Albert; Bogdasarov, Maksim (2013)."Forgery and simulations from amber" [Подделки и имитация янтаря]. In Kostjashova, Z. V. (ed.).Янтарь и его имитацииМатериалы международной научно-практической конференции 27 июня 2013 года [Amber and its imitations] (in Russian).Kaliningrad:Kaliningrad Amber Museum, Ministry of Culture (Kaliningrad region, Russia). p. 113.ISBN978-5-903920-26-6. Archived fromthe original on 16 February 2020. Retrieved9 July 2016.
