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Russian Gemstones Encyclopedia

Vladimir Bukanov. Russian Gemstones Encyclopedia

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

RESIN


RESINS group (Harze—Résins——молы) Bioorganic formations of the group of floragenic materials are classified into modern resins, fossil resins and artifical resins - plastics.

Modern resins. They are excreted by trees after physical damage; there is balsam or turpentine – a solution of resin in essential oils, and also gum – thick juices. Gums are classified into modern gum and fossil gum, including amber, described in a separate entry. Modern resins are soft resins; some of them have passed only the initial stage of petrifaction. They look like amber and they are used for its imitation or as rough material for manufacturing of varnishes. To resins also shellac and its analogues are classified.

Shellac, or natural varnish is a natural resin formed on some tropical trees as a result of vital functions of insects living on them. Its softening temperature is 65-75°C, its melting temperature is 115-120°C. In India and in South East Asia, it can be represented with tumors and complete resinous covering of branches of trees. Shellac as itself is the name for melted and purified resin of orange and dark brown color. It can be colored yellow with orpiment powder and it is used for manufacturing of bracelets and other ornamental produce. It is used as well as varnish and for imitation of amber. Mastic is a resin of a tree growing on the Greece of Chios Is. It looks like an amber-yellow mass; it is used mainly as varnish or in mixture with other resins. Sandarac is a fragile transparent yellow resin, received from Africa. It is formed on juniper, that’s why it is called juniper resin. Sandarac was used as an addition to more soft resins because of its hardness. It is used as spirit varnish, as protective covering for wooden produce. Rosin is received from resin of modern pines, evolving it through distillation from turpentine. In China, they make sometimes jewelries with such imitation of amber as rosin covered with varnish.

Dammar is a light-colored resin received from leakages on some trees. It is named after the dammar pine, on which it is formed in South India and Malaysia. Its most valuable variety is known as pine resin, or white dammar, its black variety – black dammar, and fragments found on the ground – dammar stone. Similar resin in East India, found in the form of leakages, is known as dammar cat’s-eye, or resin cat’s-eye. The mixture of these resins, sending through Singapore, is called Singapore dammar, and sending from the Kalimantan Is. – pontiac. These resins, when accumulated, get harden, and after the death of trees they are kept in soil. In the trade they are joined with copal.

Kauri is a hard resin formed on giant trees of the Northern and Southern Iss. of New Zealand, as well as in Australia and on the islands of the Pacific Ocean – Fiji and New Hebrides. Kauri is found mainly in half-fossil state, at the depth up to 10 m., as fragments up to several dozens cm. in cross-section. This chalk-white resin is well kept, but it can be easily polluted up to black color; it can contain up to 75% of admixtures. The age of kauri is not less than several thousands years. In New Zealand, it is called capia, and also kauri copal, or New Zealand ambrit. The most part of this resin was taken to Great Britain and America, where it was used for manufacturing of varnishes. The maximum volume of 10,000 tons the export has reached in 1900. From large fragments of this resin they made souvenirs in the shape of heads of Maori men, which were painted with oil-paint. For tourists they still make polished jewelries from kauri.

Copal, from copalli – “resin, incense” in one of the Indian languages of North America. It is a big group of resins of the composition: carbon ~80%, hydrogen ~9%, with hardness about 2 and density – 1.04-1.06 and melting temperature – 150-200°C. All of them are fragile, translucent, and yellowish-brownish in color. They are often fossil petrified resins of ancient tropical trees, resembling amber and hardly dissolved in usual solvents. They are also found in different parts of the world, on modern trees as resinous excretions. The age of fossil copal is not more than a hundred of years. Deposits of copal are known in Azerbaijan: Gyulistanskoye in the Khanalar Region, Gorchu in the Lachin Region. Modern source of copal in South America is giant locust. It reaches 30 m. high and 7 m. around. Fragments of Colombian copal, or Brazilian copal reach more than 2 kg. in weight. Color of copal can be from almost colorless to yellow-brown. It hardens quickly, sometimes it is found in a petrified state in the depth of the first meters in peat bogs. A similar, hard variety of it is East-African copal, or Zanzibar copal. On the Atlantic coast of West Africa, in Guinea, from the mouth of the Forecaria River to the Fatala River, they find fragments of Guinean copal up to 5 cm. in size. Its findings are also known in other African countries, for instance: in Congo – Congo copal, in Tanzania – Tanzanian copal, in Sierra Leone and on Madagascar, as well as in New Zealand, on the Philippines, in Australia. In China, produce copal is used sometimes for imitation of amber. In the Victoria and Albert Museum, London, there are several such adornments. They make beads and other work of art from copal usually covered with varnish for additional strength.

Gutta-percha – natural plastic is received from latex of gutta-percha tree. In the 19th cent., in America, they made adornments from this material, but these produce have not been preserved till nowadays because of their low durability. That’s why this material is of no importance in jewelry, all the more real plastics were invented in the early 20th cent.

Varnish is a juice of varnish tree growing in Northern Vietnam and other countries of Indochina. On the surface of a wooden thing it displays different tones of color and it makes timber stable to humidity. This varnish is used for drawings on caskets and other artistic work of art. Manufacturing of lacquered things is an ancient trade and art of Vietnamese. To make the palette broader they use tinsel gold and silver, and white color is received with gluing of egg’s shell on the surface of a work of art.

Ambre is a soft, wax-like substance of the group of bioorganic compositions, which is formed in the internal organs of sperm-whales as a protective mean against illnesses. Its density is 0.78-0.92. It is used as a fixing agent of perfume scents. Gray ambre is taken for amber sometimes, because of their similarity. In the Metropolitan Museum of Art, New York, the U.S.A., there is an adornment of J.P. Morgan, a famous collector. It is a piece of gray ambre decorated with precious stones, which was bore as an amulet of fertility, obviously.

Bezoar, from ancient Babylonian “bel” – lord and “zaar” – poison; or from Persian “be” – without and “zarar” – defect, harm, after its supposed ability to resist to poison. It is found in the form of stone-like, bluish-gray bioconcretions, which are formed in the alimentary tract of ruminants. It looks like an acorn with a lamellar texture. Properties. hardness 1-2, greasy on touch. Color: black with reddish tone to green one. It is of the class of bioorganic compositions. In the origin it is like gray ambre. Its excretions were found in stomachs of goats in Iran, India and Peru. The size of such excretions reached that one of a goose egg. The Russian Tsar Fedor Alexeevich had a silver bowl with a bezoar stone, or a bezui, put into a lid from the inner side. This material was in honor of the British Queen Elisabeth I and the Swedish King Erick XIV. A Persian Shah had sent a bezoar stone as a gift to Napoleon I, but unfortunately the has ordered to throw a stone away. Modern researches prove the ability of bezoar stone to absorb actively arsenic compounds, which were among the main poisons of the Middle Ages. Trust to bezoar stone was kept even in the 19th cent. In the antique times, in Ancient Greece and Ancient Rome, they attached magical properties to different bioorganic concretions. Pliny the Elder mentioned “rock crystal-like alectoria” from a cock’s stomach, a stone from a swallow’s stomach – purple chelidoniy, a stone from a hyena’s stomach – hyeniy, a stone from a turtle – chelonite.

Fossil resins were formed as a result of oxidation and polymerization of natural resins of coniferous-deciduous trees, which existed in the Cretaceous period. Fossil resins are linked mainly with carboniferous layers. Their general name is resinous, and diversity depends on the differences of their composition and conditions of formation. In the age and properties fossil resins are classified in “non-ripe” – soft resins of the Quaternary period and fragile resins, as well as viscous resins of the late Cretaceous and Neogenic epoch. Soft resins are described higher, some of them are found in half-fossil and fossil state, for instance: kauri, copal and copalin. Viscous resins of the group of amber are described in a separate entry. Lower, there is a description of fragile resins only. Fragile resins were passing through a long process of petrifaction. The widespread sample of fragile amber is the family of retinite. Retinite, from Gk. “retine” – resin, it is the general name of the group of fragile resins. Their properties: hardness 1-2; density 1.05-1.2. Of another group are the family of copalite with the melting temperature 165-250°C; hardness 2.5-3 and density 1.09. Sometimes these resins are used in jewelry. There are more than 120 varieties of fossil resins, some of them are represented in the App. 18.

Deposits. Amber-like fossil fragile resins are wide-spread in non-metamorphic sedimentary rocks from Eocene to Cretaceous age. On buried or modern placers they form significant accumulations sometimes. In Russia at the Primorskoye deposit, Kaliningrad (form. Königsberg) Region, fragile resin takes not more than 2% of the general volume of the extracted amber, whereas at deposits of older age this ratio can be just the opposite. Fossil fragile resins are represented mainly with gedanite and only in a few quantities with glessit, stantienite, beckerite and krantzite. In the North-Siberian amber subprovince, findings of fossil resins in carboniferous layers, mainly in cretaceous ones, can be observed from Novaya Zemlya and Pay-Khey Khrebet to Chukchi Penin.. On the Pay-Khey Khrebet, among Holocene sands, in the Amderma area, the dominating component is gedanite. In the Middle Urals, in the Yekaterinburg Region, in Paleogen clays with brown coal, near Kamensk Ural’skiy, they found krantzite called pyrite amber. In the north of the Krasnoyarsk Region, in the Khatanga River, fossil resins are represented mainly with retinite, a lesser degree with gedanite and more rarely with valchovite. Also, with retinite in Yakutia are represented fossil resins in Neozoic carboniferous rocks up the Yana River to the Inidigirka River. On the Chukchi Penin., in upper-cretaceous sands on the Anadyr’ River they found Chukchi schraufit and Chukchi wheelerite.

Far-Eastern amber sub province covers all the territory from the north of Kamchatka – from the Penjin River, to the southern provinces of China. Fossil resins are of Tertiary age there. Near Vladivostok, in carboniferous layers by Artiom, they found Ussurian retinite and fossil copal. A similar amber-like resin was found in Japan, in tuff sandstones, near Komodo, and in China, in the Liaoning Prov., at the Fushung carbon deposit, near Shenyang (Mukden) Mukden retinite.

In American amber province, fossil resins linked with deposits of brown coal and lignites are widespread, as well as placers formed in the process of their wash-out. In North-American province, they found the following varieties of fossil fragile resin: in Greenland – Greenland schraufit from brown coals; in Canada – Canadian retinite from bituminous coals of British Columbia, in Cedar Lake, Manitoba – chemawinite. In the U.S.A., in the Washington State – Washington retinite from brown coal, in the Utah State from fossil coals – köeflachite; in New Mexico – wheelerite; in Kansas – gelignite, or kansasite; in Maryland – Maryland retinite; in South California – ambrosine.

In Carpathian amber subprovince, in the Ukraine, in Zakarpats’ka territory, they find Halycija schraufit. It is deposited in sandstones of the Lower-Oligocene age, it is often transparent, brown-red. On the territory of this province, in Romania, in sandstones of upper-Eocene age, in the basin of the Moldova River, they found mukite, romanian schraufit, black almaschite, also called piatra; along the Olt River – muntenite, and in the region of Ploe¸ sti – romanian copalite.

In other regions of the world, fossil fragile resins are found in the Caucasus states, where in carboniferous rocks fossil copals of cretaceous age are spread. In Azerbaijan, there is the Lachinskoye deposit in Nagorno Karabakh; the Verkhne Adjekend deposit near Kirovabad, where they find bright red copal in nodules up to 30 cm. in size. In Armenia, there is the Kotkend deposit of copal, and in Georgia, there is a deposit near Tbilisi. In Great Britain, among brown coals of Eocene age in Devon, they find big excretions of retinite, and in Yorkshire at Middleton locality – middletonite, in Lancashire – skleretinit, in the surroundings of London – London copalite, haigeit or Haigeitian resin, and in coals of Scotland – Scottish ambrit. In Italy, from Eocene brown coals near Albom, they extracted large solid masses of trinkerit. In Spain, in cretaceous rocks of Asturias, they find Spanish retinite. In Austria, in cretaceous coaly marls of Styria, near Hieflau, they find Austrian tinkerit; and near Köflach – köeflachite; near Jauling – jaulingite in lignite from leakage on fir; and to the south, near Klagenfurt – rosthornite; in the surroundings of Vienna, near Hutteldorf, they find Austrian ambrit in the form of inclusions 4x5 cm. in size; near Hablitz – Hablitz copalite, near Lunz – Austrian copalite. In Hungary, in upper-cretaceous coals, near Ajka, they found ajkaite in the form of excretions up to the size of a poppy-head, and in the Ukraine, at middle-Oligocene sediment horizon Kiscell – kiscellite. In former Yugoslavia, in upper-cretaceous sand-clay rocks, they find telegdite in excretions up to 2 cm. in cross-section. In Czech Rep., in Cretaceous brown coals of Moravia they find transparent excretions of Moravian retinite, and also mukite, neudorfite, Bohemian ambrit and valchovite, or Moravian amber up to a human head in size. In Slovakia, in brown coals near Plauz, they find plauzite, and near Duxa – duxit. In Germany, in brown coals of Tertiary age, in the region of Bernburg, to the south from Magdeburg, they find krantzite; by Berlin, near Bitterfeld – scheibeit; in the North Rhine-Westphalia, near Siegburg – siegburit, and in Bavaria, near Bayershof – euosmite. In Switzerland, in similar bedding rocks, they found allingite, or schweizer amber. In Greece, in brown coals of the Thessaloniki Region, they find thessaly an retinite. In South Lebanon, in brown coals of Cretaceous age they found two varieties of fossil resins: the first one was Lebanese retinite, almost colorless and transparent; the second one was Lebanese schraufit, blood-red. In Indonesia, in Tertiary brown coals of the Kalimantan Is., they observed knotty accumulations of köeflachite, and in quaternary soils of the Philippines they find Indian copal and kauri copal. In the Argentina, fragile resins are represented with argentina ambrit of Tertiary age.

Synonyms. Agathocopalite | Almaschite, after the discovery location on the Alma River, Romania | Ambrit (amberit), after amber, because of their similarity | Ambrosine, after amber and resin | Beckerite, after one of the owners of a Germ. firm, worked out the deposit of amber in the Baltic Region | Chemawinite (chemoinite), after the discovery location, an Indian name for the Hudson Gulf – Chemawin, Manitoba, Canada. | Euosmite, from Gk. “osme” –– pleasant scent | Gedanite, after the discovery location near Gdansk, Poland | Glessit, from Germ. “Gleiss” – luster | Jaffaite | Jaulingite, after the discovery location near Jauling, Austria | Jelinite, after the researcher G. Jelinskiy | Kopal, Germ. | Krantzite, after the Germ. manufacturer F. Krantz | Middletonite, after the discovery location near Middleton, England | Mukite, after the German geologist Muk | Muntenite, after the Romanian mineralogist G. Muntenu-Murgozi | Neudorfite, after the discovery location near Nové Mxsto, Czech Rep. (Germ. Neudorf) | Piatra, after the discovery location near Piatra Neamx, Romania | Black resin | Haigeitian black resin | Rosthornite, after the Germ. mineralogist F. von Rosthorn | Schraufit, after the Austrian mineralogist A. Schrauf | Skleretinit, from Gk. “skleros” – hard | Stantienite, after one of the owners of a Germ. firm, worked out the deposit of amber in the Baltic Region | Telegdite, after the Germ. researcher K.R. von Telegd | Trinkerit, after the geologist Trinker | Valchovite, after the discovery location near Valchov, Czech Rep. | Wheelerite, after the Amer. researcher G.M. Wheeler.

Treatment. In jewelry fragile resins are hardly used, because of their fragility they are almost non-available for mechanic treatment, that’s why they are used mostly as varnishes. Meanwhile, they are used sometimes as a base for imitations of amber.

Artificial resins – plastics, from Gk. “plastice” – modeling, in other words, material available for modeling. There are artificial materials of the group of the imitations of gemstones. Hardness 1.5-2.5. Density 1.1-1.9. Glass luster. Thanks to technology of manufacturing of plastic produce, they are rather cheap substitutes of some gemstones and bioorganic jewelry materials. In the composition of plastics, there are often represented loading, plasticizers and different dyers. There are many trade names for them. According their properties, plastics are classified in two main groups: a) Thermo-softening plastics – on the of nitrate base; b) Thermo-stable plastics – on the base of cellon and phenol-formaldehyde resins. Thermo-softening plastics can be put into the secondary formation under heating and pressing. Thermo-stable, or thermo-reactive plastics harden under heating only and usually they are not softening under the secondary heating, for instance – bakelite or catalin. They were used for imitation of amber, jet, pearls, ivory, and tortoise shell.

One of the first thermoplastics was celluloid, named after cellulose and Gk. “eidos” – possessing the shape, with density 1.38-1.42. It was invented in 1860 as a result of the competition for inventing of the substitute of ivory and it was patented in America in 1870. The winner of that competition was the American inventor John W. Hite, who invented a machine for manufacturing of billiard-balls later. Material for them was known in Britain plastic – xylonite, which was renamed by J. Hite into celluloid. Its yellow variety is antique ambre, there are also such incombustible varieties cellon, or lumarite and rhodoid. Of the same group is pyraline, which is used for imitation of gemstones. Its hardness is 1.5-2, density – 1.2-1.6. The most modern of them is the imitation of the type of ceramic – ivorine from the mixture of several powders. It is well polished, looks like ivory in color, density, thermal conductivity and porosity.

Thermo-stable plastics – protein resins. Among them the most widespread is casein or erinoid, invented in 1890 in Germany and known under the trade name galalite; with density 1.32-1.34. It is made from milk protein under heating of it with an acid; galalite, from Gk. “milk” and stone. Erinoid is colored easily. Its variety lactoide is used for imitation of agate, jet, coral, ivory, malachite, tortoise shell, bone, amber and other ornamental materials. In Japan, it is called ambloid, but there are 55 other trade names for it.

Ebonite was the first artificially made plastic, which was used as a jewelry-ornamental material at once. In America the method of its manufacturing was patented in 1846. It was produced from the mixture of rubber with 30% of sulfur with following heating of the product up to the temperature of 115ºC. Ebonite is rather light in weight, even black in color, well polished and formed under low heating. So, produce from this material can be easily replicated. They made brooches, pendants, and chains from it. In the Victorian Britain, this material was successfully used for imitation of fashionable jet. The only defect of ebonite was the instability of its color in the direct sunrays. After a while, it gets brown and, then, khaki, and, at the end, dirty-yellow.

Bakelite is a phenol-formaldehyde resin, the first synthetic plastic. It was patented by L. Baleland in 1909. Similar to the other thermo-stable plastics, it can be formed. In 1916, they made an imitation of amber from it, and black bakelite was used as a substitute of jet in manufacturing of beads, brooches and bracelets. In the East, red bakelite is sold in such produce as Burmese amber. Transparent produce from such plastic is manufactured with the method of castings. Nowadays this plastic is called resol. For colored phenol plastics being used for imitation of gemstones there is also such name as micatite.

Polystyrene is a popular plastic, which was used for imitation of amber. It is produced with the method of polymerization of styrene – a liquid received from aroma resin of styrax tree. In Great Britain, it was known as distene; in the U.S.A., as styrol, lustron, victron; in Germany as rosoglanz and troletul.

Acrylic resins are transparent plastics, coltstone, which are often used for imitation of gemstones, for example plexiglas, perspex or diakon. From acrylic resin they received an imitation of Slocum amber and an imitation of opal on the base of glassSlocum stone, where colored cellophan played the role of loading.

Polyester resin was used as a base in produce with amber mosaic under the trade name polybern. An imitation of amber from such resins is called bernat or bernit.

Epoxy resin is the latest of thermo-stable plastics, which is used for imitation of gemstones. The first patent on it was given in Germany in 1939. The defect of this resin is its shrinkage after hardening. One of the main ways of its usage in imitations is covering to strengthen the mechanic stability of the surface of soft resins of the type of copal, smelted amber and gemstones with low hardness. In the Museum of the Cathedral in York, Great Britain, there is a black cameo, 46x56 mm. in size, with a portrait of Dante, made of polyester resin.

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