gems, beryl, emerald, synthetic emerald

Large single crystals of synthetic emerald have been grown by both hydrothermal and molten flux techniques. The synthetic hydrothermal emeralds are of excellent quality comparable to the finest natural gemstones from Colombia and the Ural Mountains.

emeralds, Colombia, gems

Sinkankas: The text is in four parts, with the first treating legends and lore and much on the emerald as it was known to the pre-Conquest Indians in the Muzo region, emeralds elsewhere in the world, famous jewels and gems employing emerald, including remarks on the famous “Patricia” crystal now in the American Museum of Natural History in New York, and other generalities. The second part is a chronology of events from the first appearance of Spaniards on the scene, their attempts to find the deposits, subsequent discoveries and mining, and further events into the present. Part three describes the administration of the mines by the Banco de la República from the 1940s up to now, with much information on the mines, decrees, regulations, production statistics, etc., on Muzo and other emerald mines in Colombia. Also in this part is material on synthetic emeralds, properties and values of same, beryllium resources in Colombia, drawings of emerald crystal forms and cutting styles, properties of cut gems, the formation of emerald, composition, “gemelos” or “trapiches,” the lapidary industry, etc. The last part reproduces important geological and mineralogical documents concerning the deposits, including some by Miguel Gutierrez, Robert Scheibe, Peter W. Rainier, Miguel Alvarez Uribe, Roberto Wokittel, H. Bürgl, E. Hubach, Hernan Restropo, and E. Nicholls. Works by Scheibe, Rainier, Restropo, and Wokittel are described under their names. The text also gives short biographies of Scheibe, Wokittel, Fritz Klein, and Barriga Villalba. The author was in a position of authority in the Banco de la República which enabled him to construct with unparalleled accuracy historical portions of the present work with the best yet information on the Colombian emerald mining industry. Unfortunately, not as much attention has been paid to assembling information on the mineralogy and parageneses noted in the deposits nor to compare views on the vexing problem of their origin.

corundum, history.1, gems, jade, Fischer-Other, Rome, ancient gems, glyptic

This volume contains Books 36 and 37 of Pliny the Elder’s Natural History, with the Latin text and D. E. Eichholz’s English translation on facing pages. Book 36 deals principally with stones and their uses in architecture and sculpture, including celebrated works in marble, notable buildings and monuments, obelisks, pyramids, and accounts of various building and ornamental stones. Book 37 is devoted largely to gemstones and other precious materials and is particularly important for the history of gemology. Pliny discusses the origins, properties, varieties, uses, values, and supposed virtues of numerous gems, including rock crystal, amber, diamond (adamas), emerald (smaragdus), beryl, opal, sardonyx, amethyst, carbuncle and other stones, while also recording methods of testing, imitating, and falsifying gems. He draws extensively upon earlier Greek and Roman authorities and combines observations of trade, mining, craftsmanship, collecting, and connoisseurship with the mineralogical and medicinal beliefs of antiquity. Book 37 concludes the Natural History and provides one of the most extensive surviving ancient accounts of gemstones, making it a fundamental primary source for the study of gemology and the gem trade in the classical world. Book 1: table of contents of the others and of authorities; 2: mathematical and metrological survey of the universe; 3–6: geography and ethnography of the known world; 7: anthropology and the physiology of man; 8–11: zoology; 12–19: botany, agriculture, and horticulture; 20–27: plant products as used in medicine; 28–32: medical zoology; 33–37: minerals (and medicine), the fine arts, and gemstones.

gems, beryl, emerald, Colombia, Muzo, Chivor, Cosquez

Restrepo presents a reconnaissance study of the Muzo and Coscuez emerald mines in Boyacá, intended to provide a basis for more detailed geological investigation and systematic prospecting. The emerald-bearing rocks are described as strongly folded Lower Albian black pyritic shales cut by numerous fractures, chiefly filled with crystalline to white calcite, within the fault-bounded Muzo–Coscuez horst. Emerald and other beryl are regarded as primary minerals occurring within calcite-filled fractures and druses; emerald-bearing fractures are generally 2–10 cm wide, and emerald constitutes less than 1% by weight of their contents. Restrepo considers three possible origins for the mineralizing solutions: magmatic pegmatitic solutions, solutions produced by ultrametamorphism or anatexis, and pneumatolytic-metasomatic solutions, without selecting one conclusively. He proposes a paragenetic sequence in which quartz, feldspar, beryl (emerald and morralla), possible parisite, apatite, fluorite, and mica are primary, followed by secondary replacement minerals including calcite, dolomite, barite, and pyrite, and later oxidation products. Published measurements of Muzo emeralds are reviewed, including refractive indices ranging approximately from 1.564 to 1.598 and chemical analyses, while chromium and vanadium are discussed as possible causes of the green color. The report also describes contemporary open-pit mining and hand recovery of emeralds, considers the possibility of recovering microscopic beryl from waste by flotation, and recommends detailed geological, mineralogical, petrological, structural, and mining investigations to improve exploration of the Muzo–Coscuez district.

beryl, emerald, Austria, gems

corundum, history.1, gems

The history of jewelry has closely paralleled the history of mankind. Used as amulets to protect against harm and worn for ceremonial occasions, jewels also signaled wealth, power, and position. This engrossing scholarly study by a noted English antiquarian offers a splendid account of jewelry styles over a 700-year period — from the early Middle Ages and Gothic period, through the Renaissance as well as the seventeenth, eighteenth, and nineteenth centuries. Drawing on a number of vital sources — museums and private collections, evidence given by portrait painters, surviving designs for jewels and others — the author gives us not only a comprehensive chronicle of the jewels themselves but also their relation to costume and fashion and their reflection of changing social values. Enhancing the meticulously detailed narrative are 400 photographs and illustrations depicting, among scores of other pieces, a gold heart-shaped brooch inscribed with You are my earthly joy," dating from the fifteenth century; a gold brooch set with sapphires, emeralds, and pearls; a diamond and topaz necklace (c. 1760); a gold padlock, set with cornelian and pearls (c. 1800); a gilt bronze clasp (c. 1200); the silver Loch Buy Brooch, set with rock crystals and pearls (sixteenth century), and a thirteenth-century reliquary pendant of the Holy Thorn. For anyone interested in the long and fascinating history of handcrafted jewelry, here is a superb sourcebook of extremely rare ornamentation, a rich and detailed study that will also appeal to fashion and costume historians, collectors, and lovers of antiques."

gems, inclusions, corundum, ruby, sapphire, beryl, emerald, spinel

gems, beryl, emerald, India, Rajasthan

During World War II, an intensive search was conducted in Rajputana for high-quality beryl and mica. Among those actively involved was Sir Bhagchand Soni, a prominent banker and financier in Ajmer, who financed prospecting parties across a considerable area in north-western Mewar. Although both mica and beryl were found, the deposits ultimately proved commercially disappointing. However, prospectors sent some small green beryl crystals to Sir Bhagchand, who forwarded them to the Mica Production Section of the Geological Survey of India in Ajmer for analysis. While the report could have dismissed the crystals as ordinary green beryl of little value unless found in large quantities, it happened that the Officer-in-Charge had recently seen boxes of crude Russian emeralds unpacked by a major lapidary firm in Jaipur. Recognizing that the Mewar crystals matched the quality of the Russian specimens, he identified them as beryl of the emerald variety and recommended that Sir Bhagchand secure a mining lease for the area. This is the first documented occurrence of emerald in India and thus an important paper.

gems, early science, early optics, Arabic mineralogy, Arabic science, eyeglasses, sunglasses, beryl, aquamarine, Ptolemy, early lapidaries

In classical literature, mention is sometimes made of the magnifying power of transparent media, but it is improbable that magnifying glasses were known in Europe before the 13th century. Ptolemy, who lived at Alexandria around A.D. 150, gives some details concerning lenses and discusses the course of rays of light passing from one medium into another, but as the last part of his famous treatise on optics is lost, one cannot tell how extensive his knowledge was. It was the Arab Alhazen (circa A.D. 1000) who wrote on magnifying glasses. He describes how objects, when seen through a segment of a sphere with an index of refraction greater than that of the surrounding air (“grossius aere”), appear larger than they are in reality. This optical effect of lenses is not described in European literature before the 13th century. It is generally held that Roger Bacon (c. 1214–1294) was the first European scholar to mention the practical utility of lenses. In his Opus maius (written 1266–1267), he describes how to magnify writing by placing a segment of a glass sphere on the text with its plane side down. But, as shown elsewhere, there was another Englishman, Robert Grosseteste (1175?–1253), Bishop of Lincoln, who anticipated Bacon. In his treatise De iride seu de iride et speculo there is a passage which can be translated thus: “…it will be perfectly clear… how far and how large and in what shape a body, of which the distance, size, and place are known, will appear to the eye, when there is a diaphanous body, of which the distance, size, and place are also known; and it is clear in what manner transparent bodies must be moulded, so that they may receive the visual rays, emanating from the eye, under an angle as wide as they wish it, and how they may collect the rays on the visible objects, whether those objects are big or small, far or near; and so they may see each visible object wherever and in any size they wish; and they may operate, so that very long objects appear to be short and, in contrast, that very small and far objects are clearly visible.” As far as I know, Robert Grosseteste was the first scholar in Western Europe who wrote on optics, and so he deserves well of science. There was a third Englishman who had great merits in connection with optics—John Peckham (1228–1294), Archbishop of Canterbury, renowned for Perspectiva communis, a book which appeared in subsequent centuries in several printed editions.

corundum, quality.10, India.12, Tajikistan.12, spinel, gems, Indian lapidary

Aziz’s The Imperial Treasury of the Indian Mughuls examines the extraordinary wealth accumulated by the Mughal emperors and the organisation and contents of the imperial treasury. Drawing on contemporary chronicles, travellers’ accounts and other historical sources, the work describes the vast quantities of gold, silver, jewels and precious stones held by the Mughal court, together with jewelled ornaments, ceremonial objects and other valuables. Particular attention is given to diamonds, rubies, emeralds, pearls and other gems, including celebrated stones associated with the emperors and the ways in which such treasures were acquired, valued, stored and displayed. The study also places the treasury within the wider setting of Mughal court life, where gemstones and jewellery served not merely as stores of wealth but as important symbols of sovereignty, rank and imperial magnificence.