gems, beryl, emerald, Colombia, Muzo, geology

The Muzo Emerald Mines represent the only large emerald deposits that can be successfully mined and that produce the highest quality emeralds known. Although mined in a very primitive way for the last 400 years, Muzo still has quite unpredictable emerald reserves, which do not seem to have diminished after centuries of mining. The invariable relation of the Muzo emeralds with the Cretaceous Villeta shales is quite peculiar and has not yet been given an adequate explanation.

synthetic corundum.7, gems

This three-part series reviews methods available in 1946–1947 for distinguishing synthetic corundum, spinel, and emerald from their natural counterparts, emphasizing microscopic examination of inclusions and growth structures. R.T. Liddicoat introduces the distinction between a synthetic gem, which reproduces the chemical composition and atomic structure of its natural counterpart, and an imitation marketed under an inaccurate name. Materials sold as synthetic alexandrite, zircon, garnet, or aquamarine are described as corundum or spinel substitutes identifiable by their different properties. For natural and synthetic corundum, however, ordinary refractive-index and density measurements provide little assistance, making internal features particularly important. Natural ruby and sapphire are illustrated by fingerprintlike fluid inclusions, zircon crystals with surrounding fractures, oriented silk intersecting at 60°, and straight or hexagonally arranged growth zoning. Synthetic material produced by the Verneuil process is characterized by spherical or elongated gas bubbles and curved growth striae. The authors explain that nearly flawless specimens require higher magnification, careful control of illumination, examination from different directions, and sometimes immersion to reduce distracting surface reflections. E.J. Gübelin expands the discussion of gas inclusions, describing isolated bubbles, localized clouds, and concentrations following growth layers, while noting that improvements in production reduce their abundance and size. He cautions that subsurface cracks caused by rapid polishing occur in both natural and synthetic corundum and therefore do not establish synthetic origin. The third installment treats synthetic spinel separately because curved striae are absent from the material examined. Its gas inclusions may be spherical, tubular, wormlike, or irregularly elongated, while characteristic strain patterns under crossed polarizers provide further evidence. Gübelin contrasts the cloudy, fibrous, or feathery anomalous birefringence of synthetic spinel with the generally fainter, less sharply defined patterns observed in natural specimens. Synthetic emerald presents a different problem because its slower crystallization can produce straight or hexagonal zoning resembling natural growth. Slightly lower refractive index, density, and birefringence are discussed as supporting distinctions, but microscopic features receive greater practical emphasis. These include scattered minute solid particles, undulating wisps or feathers described as groups of small liquid inclusions containing gas bubbles, irregular cavities, and pronounced strain-related anomalous birefringence. Gübelin treats the identity of the scattered solid particles as uncertain, tentatively suggesting coloring material. Recommended observation methods include dark-field microscopy, transmitted light, crossed polarizers, and immersion, with the lighting selected to reveal particular structures. Spectroscopy and luminescence are mentioned as supplementary approaches when microscopy proves insufficient. Throughout, the series presents identification as a matter of recognizing diagnostic internal features while avoiding conclusions based on ambiguous cracks, superficial resemblance, or the absence of conspicuous imperfections.

gems, bery, beryl, emerald, Pliny, history of gemology, etymology, Rome, Roman gemology

Pliny the Elder’s chapters on the smaragdus are so lacking in scientific detail that it is impossible to identify exactly the different minerals he includes under this term. Of the twelve varieties he mentions, the first is most probably the only one that ought properly to be translated as “emerald”: quantum smaragdi a gemmis distant, tantum Scythici a ceteris smaragdis. There are, however, two clues in the passage which, considered in light of information provided by other writers, help explain the broad application of the word smaragdus. The mineral in question may have been a hydrated carbonate found in many parts of the world, from Cornwall to Chile. Although its pleasing green color led to its use for ornamental purposes, its opacity excludes identification with at least some of the nine varieties associated by Pliny with copper (37.66): dos eorum est in colore liquido nec diluto, verum ex umido pingui quaque perspicitur.

corundum, beryl, emerald, inclusions, synthetic beryl, emerald, gems

This illustrated series presents gemstone inclusions as practical evidence for identification, distinguishing natural from synthetic stones, and interpreting the conditions under which gems formed. Drawn from Gübelin’s photomicrographic studies and a collection of Kodachrome transparencies supplied to the Gemological Institute of America, the installments combine explanatory text with photographs and descriptive captions. Microscopic examination, particularly with dark-field illumination, reveals structures that may be overlooked or misinterpreted with a loupe. The sapphire section illustrates oriented needles and silk, angular growth zoning, mineral crystals, fluid cavities, and featherlike networks. Examples include hematite plates, enclosed corundum crystals, and cavities containing liquid and gas. These features are compared with curved growth striae and gas bubbles in synthetic sapphire. Gübelin cautions that appearances can be deceptive: natural cavities may resemble bubbles, while the curvature of synthetic growth lines may be difficult to recognize within a small field of view. The ruby installment similarly contrasts natural rutile arrangements, straight structural features, mineral inclusions, and fluid-related formations with curved striae and concentrations of gas bubbles in synthetic material. Zircon inclusions surrounded by halos and intersecting rutile needles illustrate characteristic internal features of individual specimens from Sri Lanka and Myanmar. The emerald section describes enclosed crystals, irregular cavities, and inclusions containing liquid, gas, and a solid phase, while comparing these with wispy formations and other internal features observed in synthetic emeralds. The diamond installment demonstrates the importance of illumination when interpreting dark inclusions: objects commonly regarded as black or carbonaceous may prove to be transparent crystals when examined appropriately. Photographs show enclosed crystals, including diamond, together with cleavage features and fractures associated with inclusions or extending inward from the surface. Subsequent installments broaden the survey to additional sapphires and other gem materials. Illustrated examples include fine networks of channels, negative crystals, mineral plates, zircon-associated halos, liquid inclusions with mobile bubbles, and cavities containing separate liquids. Topaz and tourmaline provide further examples of fluid-bearing inclusions, while the concluding selection extends the illustrated material to emerald, peridot, quartz, garnet, and moldavite. Biotite flakes in peridot and fibrous actinolite in quartz demonstrate the variety of solid inclusions; a fluid-bearing negative crystal in citrine reproduces the host’s prismatic form. Throughout the series, the diagnostic value lies in the combined character, arrangement, and appearance of internal features rather than in an isolated resemblance. Gübelin advocates making inclusion study an early part of gem examination, potentially preceding routine measurements of physical and optical properties. The series also emphasizes the scientific and aesthetic interest of microscopic structures, presenting gemstone interiors as records of mineral growth and subsequent events as well as aids to identification.

gems, jade, jadeite, fei cui, ladies of jade

An autobiography of Hui-Lan Koo (née Oei Hui-lan), daughter of the wealthy Chinese-Indonesian businessman Oei Tiong Ham and wife of the distinguished Chinese diplomat Wellington Koo, as recounted to Mary Van Rensselaer Thayer. The book traces her privileged childhood in Java, her family's commercial empire, her education and travels in Asia and Europe, and her marriage to Wellington Koo in 1920. Much of the narrative concerns her experiences in international diplomatic society during a turbulent period in Chinese history, including the League of Nations, the Washington Naval Conference, the political instability of Republican China, and the Japanese invasion of Manchuria. Particularly noteworthy are her descriptions of Chinese customs, elaborate wedding ceremonies, court etiquette, luxury, fashion, and jewelry. The book contains numerous references to precious stones, including diamonds, emeralds, rubies, pearls, and jade. Her mother possessed magnificent jewelry, including jeweled hairpins and matching parures set with diamonds, emeralds, and rubies. During a childhood visit to Burma, Hui-Lan recalled shopping for rubies that were so inexpensive that her father purchased small stones in parcels to distribute as souvenirs. Her own engagement ring was a Kashmir sapphire, and she describes wearing pearls purchased from Cartier, along with other jewels associated with her position in diplomatic society. The narrative also records the use of jade ornaments in traditional Chinese ceremonial dress, including a jade button signifying rank on a bridegroom's mandarin hat. Beyond its autobiographical interest, the work provides a firsthand account of the material culture and social customs of wealthy overseas Chinese families and the diplomatic elite during the transition from imperial to Republican China, with valuable incidental observations on the ownership, display, and cultural significance of gemstones and jewelry.

beryl, emerald, synthetic beryl, emerald, inclusions, gems

Gübelin and Robert M. Shipley, Jr., examine the identification of synthetic emerald following its introduction into the American jewelry trade, including reports of synthetic stones mixed with natural emeralds. Their account draws on five specimens studied by Gübelin and ten examined at the Gemological Institute of America’s Los Angeles laboratory. It discusses the German product marketed by I.G. Farbenindustrie as “Igmerald,” while an editorial note states that the American laboratory’s specimens came from an agent claiming independent manufacture in the United States. Synthetic emerald resembles natural material in color, luster, chemical composition, and crystal form. Unlike the pear-shaped boules associated with synthetic corundum and spinel, it develops as groups of well-formed hexagonal crystals, sometimes large enough to yield fashioned stones exceeding one carat. Straight growth bands parallel to the basal plane may occur, but external appearance and crystal habit provide little assistance in identification. The authors instead advocate combining optical measurements with microscopic examination. Their synthetic specimens show lower refractive indices and birefringence than the natural emeralds tabulated for comparison; representative synthetic values are 1.562–1.564 for the ordinary ray and 1.559–1.561 for the extraordinary ray, giving birefringence of approximately 0.003. Recent synthetic material displays relatively weak dichroism, contrasting with earlier reports of strong dichroism and indicating changes accompanying manufacturing progress. Pronounced anomalous double refraction produces birefringent patches and interference colors, attributed to internal strain probably associated with rapid growth. Previously published Laue photographs are cited as additional evidence of strain. Igmerald also exhibits absorption bands at 594 and 606 nm beyond the chromium-related features discussed for emerald; the authors propose these as diagnostic of that product and tentatively associate them with increased chromium content. Specific gravity is generally lower in synthetic material, but overlapping values limit its usefulness alone. Microscopic inclusions receive particular emphasis as a practical means of distinction. The examined synthetics lack the solid crystalline particles within fluid cavities that the authors associate with natural emerald’s three-phase inclusions. Separate minute solid particles may nevertheless occur in swarms. The most characteristic internal features are delicate featherlike, wispy, or veil-shaped formations resembling cracked lacquer or cloisonné. At approximately 250× magnification, these resolve into numerous small liquid inclusions containing rounded gas bubbles, arranged in broad, slightly curved groups. Nearly parallel rodlike features, interpreted as probable gas-filled cavities, are especially conspicuous in older synthetic material. The authors conclude that the combined evidence of refractive properties, strain patterns, absorption features, and characteristic inclusions permits reliable separation of the synthetic emeralds examined from natural stones, despite their close visual resemblance.

beryl, emerald, Russia, Colombia, inclusions, gems

Gübelin investigates microscopic criteria for distinguishing emeralds from Colombia and Russia’s Ural Mountains, arguing that color alone provides an unreliable indication of origin. Although Colombian emeralds are associated with a velvety green and Russian stones with more yellowish hues, examples from either source may resemble those from the other, particularly in small sizes. A comparative table records their appearances through several colored filters, but the author emphasizes that interpreting these subtle differences requires considerable experience, a sensitive eye, and suitable comparison material. Seeking more objective evidence, he examined numerous emeralds of known provenance, including specimens supplied by the Colombian Consulate in Paris. He identifies minute fluid inclusions, rather than conspicuous fractures or cloudy areas, as the most useful distinguishing features. Colombian emeralds are described as containing scattered, irregular groups of delicate, frequently tail-like cavities. Their boundaries are faint, suggesting that the enclosed liquid has a refractive index relatively close to that of the host. The liquid’s composition was not established, although behavior during heating and considerations of formation led the author to suggest water. The cavities show no consistent crystallographic orientation and remain separate even when grouped. Almost every cavity is reported to contain a tiny cubic crystal, commonly adjoining a rounded gas bubble with a dark outline, so that solid, liquid, and gaseous phases coexist within one inclusion. Carbon dioxide is proposed as the gas, while the solid’s chemical identity remains unresolved. Gübelin regards the cubic form of this solid inclusion as the principal diagnostic feature of Colombian material. Russian emeralds likewise contain multiphase inclusions, but their distribution, cavity shapes, and enclosed crystals differ. Their cavities are more closely associated with fractures and moss-like internal features, lack the characteristic Colombian tails, and contain solid crystals displaying lozenge-shaped or rhombic outlines rather than clearly rectangular cubic forms. The author presents this contrast as a dependable means of separating the two sources and supplies a mnemonic linking Colombian origin with cubic crystals and Russian origin with rhombic crystals. He recommends photomicrography to document the observations and notes that the features can also be examined with a diamondscope. The concluding discussion separates geographical interest from intrinsic quality: identifying a fine emerald as Russian need not diminish its value, while knowledge of provenance may increase an owner’s appreciation of either a Colombian stone or an unusually fine-colored Ural specimen.

corundum, History.1, gems, early lapidaries

J.H. Nunemaker compares a fifteenth-century Spanish prose adaptation of Marbode’s lapidary with the First French Version in verse, examining how vernacular transmission reshaped descriptions of stones and their attributed medicinal and magical powers. He situates Marbode’s popularity within a medieval intellectual framework that accepted such powers as natural properties and identifies episcopal authority as another source of the work’s prestige. The principal comparison uses the French text edited by Studer and Evans because it contains more of the stones represented in the Spanish adaptation than other French versions; for the prologues, Nunemaker instead selects the First Anglo-Norman Prose Lapidary because its wording offers a closer parallel. The Spanish work describes forty-two stones, compared with sixty in Marbode’s lapidary, and includes eight absent from Marbode that its editor, Karl Vollmöller, attributed to Isidore. Despite these differences in coverage, the sequence of shared stones remains nearly identical. Through a systematic comparison of individual entries, Nunemaker documents additions, omissions, changes of order, subdivisions, and variations in descriptive detail. He argues that prose permits the Spanish adapter to expand material presented more compactly in French verse, supplying additional geographical information, classifications, classical references, therapeutic recipes, and supernatural virtues. The Spanish treatment divides the diamond material into three separate articles, increases the stated varieties of emerald from six to twenty-two, and elaborates accounts of stones associated with marriage, protection, persuasion, and nocturnal fears. Nunemaker particularly emphasizes the greater prominence of magic, demons, and marvellous effects in the Spanish text, contrasting these passages with what he interprets as the French version’s more cautious treatment or avoidance of witchcraft. Examples include coral’s power against demonic apparitions, additional virtues assigned to the magnet, and recommendations of certain stones for people believed to be possessed. Other entries preserve essentially the same information, demonstrating substantial continuity alongside adaptation. The comparison also identifies a conspicuous textual misunderstanding in which a reference to Theophrastus becomes the name of a stone in the Spanish account of lyn curium. Rather than establishing a complete genealogy of the Spanish text, the article provides an inventory of correspondences and divergences, showing how a shared lapidary tradition could retain its basic arrangement while acquiring fuller descriptions and a more explicit supernatural emphasis in a later vernacular form.

gems, beryl, emerald, Colombia, lore

Tastefully-designed, all in same format, and distinguished by use of Rockwell Kent's characteristic drawings as vignettes on each title page in addition to a tipped-in color plate of high quality. The text is in popular vein, with a few technical facts and more on lore and legend. A second printing issued on thinner, whiter paper, and enclosed in a wrap of white, silver-flecked paper, which also used for endpapers. [from Sinkankas]

gems, ancient gemology, early gemology, ancient mineralogy, glyptic, beads, beryl, emerald

The Septuagint, or Vetus Testamentum Graece iuxta LXX Interpretes, is the ancient Greek translation of the Hebrew Scriptures, traditionally attributed to seventy (or seventy-two) Jewish scholars in the 3rd to 2nd centuries BCE. This edition presents the Old Testament text in its Greek form, preserving the linguistic and textual heritage that significantly influenced early Jewish and Christian traditions. It is a foundational text for biblical studies, particularly for understanding the development of the Hebrew Bible, its reception in the Hellenistic world, and its use in early Christianity, where it often served as the primary scriptural source.