gems, diamond, synthetic diamond, Sumitomo

The distinctive gemological properties of gem-quality synthetic yellow diamonds produced by Sumitomo Electric Industries are described; these commercially grown deep yellow single crystals reach sizes up to 2 carats, though they are currently marketed for industrial use only, typically in pieces up to about 0.40 carat. These synthetic diamonds can be identified by their ultraviolet fluorescence (inert to long-wave, greenish yellow or yellow to short-wave), unusual graining, veining, and color zoning visible under magnification, as well as the absence of distinct absorption bands in their spectra.

corundum, synthetic corundum.7, color.4, spectroscopy, Madagascar.12, ruby, gems

Gallium concentrations in emerald, corundum and chrysoberyl are evaluated as a proposed means of distinguishing natural from synthetic gemstones. Because gallium and aluminium have similar ionic radii and the same valence, gallium can substitute for aluminium in these minerals, but its abundance depends on geological conditions and the materials used in synthesis. The study tests earlier suggestions that gallium concentrations above approximately 50–200 ppm establish natural origin in corundum, that lower concentrations indicate synthesis, and that measurable gallium identifies natural alexandrite. Neutron activation analysis results obtained by the authors and incorporated from an earlier investigation cover 32 emeralds, comprising 22 natural and 10 synthetic specimens; 18 corundums, comprising eight natural and 10 synthetic specimens; and 16 chrysoberyls, comprising six natural alexandrites, two synthetic alexandrites and eight other natural chrysoberyls. The results demonstrate overlap and important exceptions to the proposed criteria. Natural and synthetic emeralds have similar gallium ranges, with several synthetic samples containing concentrations comparable to natural stones. Four natural corundums contain less than 50 ppm gallium, while only one of the eight natural samples exceeds 200 ppm. A synthetic alexandrite contains 480 ppm, exceeding the concentrations measured in the natural alexandrites examined, whereas one natural chrysoberyl contains only 2 ppm. The paper also assesses analytical limitations that complicate interpretation. Several electron-beam and X-ray methods lack sufficient sensitivity for reliable determination of low gallium concentrations, and surface measurements may fail to represent variations associated with internal zoning or structure. Neutron activation analysis is regarded as the most suitable available technique, with a detection limit of approximately 0.5 ppm and reported accuracy of 3–10% of the measured concentration. Its routine use is nevertheless restricted by cost, lengthy analytical procedures and the slow decay of induced radioactivity. The authors conclude that gallium content alone cannot reliably establish natural or synthetic origin in the gemstone groups investigated. Proposed concentration thresholds require caution, and any identification suggested by gallium analysis must be corroborated by additional tests.

corundum, treatments.6, gems

Gunawardene reports observations on yellow sapphires produced by heat treatment, particularly material from Sri Lanka. The paper examines changes in colour resulting from heating and the gemmological features that may assist in recognizing treated stones. Of particular interest is the behaviour of the induced yellow to orange-yellow colour under subsequent heating and illumination, together with microscopic evidence of thermal alteration. The study contributes to the developing understanding during the 1980s of how heating could produce or modify yellow coloration in corundum and of the practical difficulties involved in distinguishing such stones from naturally coloured yellow sapphire.

corundum, China.12, geology.11, jade, gems

A. Chikayama surveys China’s gemstone resources, concentrating on nephrite and the diverse ornamental materials traditionally used for carving and sold under regional jade names. The article presents a nationwide locality map and a comparative table linking Chinese stone names with mineralogical identities, colours, transparency, lustre, hardness, specific gravity, refractive index and principal sources. Hotan Yu from Xinjiang is identified as nephrite, while Xin Yu from Liaoning and Nan Yu from Guangdong are serpentine; Dongbei Yu from Liaoning contains serpentine and tremolite. Dushan Yu, also called Nanyang Yu, is described as a mixed rock consisting chiefly of plagioclase and zoisite, with mica and sphene. Several other materials bearing jade names are quartzites: Mi Yu from Henan is green, Guizhou Yu is blue, and Jing Bai Yu from the Beijing area is white, with dyed colours also recorded. The survey further includes tiger’s-eye from Henan, rhodonite from Beijing, turquoise from Hubei, Shaanxi and Henan, malachite from Hubei, and fluorite from several provinces. Rose quartz and amazonite are recorded from Xinjiang, with amazonite also occurring in Yunnan. Ju Hua Shi is listed as a celestine-and-calcite material with a radial structure. Pyrophyllite carving stones receive particular attention through locality-based names, including Changhua Shi, Qingtian Shi, Shoushan Shi, Mira Han Yu and Bairin Shi; Changhua material also contains cinnabar responsible for blood-red mottling. Rock crystal, agate, jasper and additional serpentine occurrences are noted more generally. Beyond carving materials, the author reports Chinese deposits of diamond, ruby, sapphire, aquamarine, beryl, peridot, pyrope garnet, zircon and topaz, highlighting blue sapphire and red zircon from Hainan Island and noting that further deposits had not yet been publicly disclosed. Institutional developments accompanying increased economic interest in gemstones include the establishment of the Gem Mineral Corporation in Beijing in June 1984 to promote resource exploitation, processing, identification, valuation and sales, and a gemmological laboratory within the Ministry of Geology and Mineral Resources in 1982. The article provides a compact reference to the geographical distribution and physical properties of Chinese carving stones while demonstrating the mineralogical diversity concealed by traditional jade nomenclature.

gems, jade, jadeite, fei cui, Mesoamerica, Mexico, Guatemala, Costa Rica, Mayans, Olmecs, Aztecs, archaeology, history, archaeogemology, Pre-Columbian jade; Costa Rica; Maya; exchange; iconography, lapidary

The Popol Vuh tells the story of the emergence of light in the darkness, from primordial glimmers to brilliant dawns, and from rainstorms as black as night to days so clear that the very ends of the earth can be seen. A revised edition of this translation of the Popol Vuh has become necessary because the world of Maya studies is itself a constantly brightening one. Advances in the understanding of Maya languages, literature, art, history, politics, and astronomy have required changes in the introduction, notes, commentaries, glossary, and illustrations. There are also changes in the translation itself, some of them subtle refinements and others that readers of the previous edition may find surprising. Finally, an index has been added. Newly available sources on Maya languages have made it possible to give meaning to proper names that were left untranslated before. For example, Xbaquiyalo, the wife of Seven Macaw, now becomes Egret Woman. The temptresses Xtah and Xpuch are now Lust Woman and Wailing Woman, and they stand revealed as the predecessors of a dangerous phantom known all the way from Guatemala to northern New Mexico by her Spanish name, La Llorona. And Tecum, Keeper of the Mat in the ninth generation of Quiché lords, becomes Black Butterfly. In other cases, new sources have made it possible to correct errors of translation that were caused by imprecise spellings or slips of the pen in the Popol Vuh manuscript, which often leave words and phrases open to multiple interpretations. What was once “the emergence of all the sky-earth” now becomes “the lighting of all the sky-earth,” a reference to the astronomical aspect of the story. The name of the first human woman, given as Celebrated Seahouse in the previous edition, now changes to Red Sea Turtle. The term for the rubber used by the Hero Twins to heal a falcon’s eye is no longer “sorrel gum” but rather “blood of sacrifice.” And the image of the god Hacauitz is no longer located “above a great red river” but rather “at the top of a great pyramid.”

gems, treatments, assembled stones, foil backing, foilback

The Gem Trade Lab Notes section (Winter 1984, p. 228) reported on emerald imitations made from colorless rock crystal quartz backed with green foil—a technique still commonly used today, even in enameled jewelry. Similarly, colorless beryl or corundum is often backed with red or green foil to mimic emerald or ruby, while silver foil may be applied behind colorless synthetic or natural sapphire to enhance its brilliance.

gems, lapis lazuli, Afghanistan, oiled lapis lazuli, gem treatments, oiling

An importer of fine lapis lazuli beads from Afghanistan noticed a variation in luster among the beads and suspected that some had been oiled to enhance their appearance. After confirming the beads as genuine lapis lazuli, the New York laboratory used a thermal reaction tester and magnification to investigate the presence of oil or paraffin. All beads exhibited the typical reaction of oil being drawn to the surface by the heated probe, with some showing heavy oil concentrations in drill holes and surface cracks. The lack of whitening upon cooling indicated the presence of oil rather than paraffin. Microscopic examination and acetone testing revealed no evidence of blue dye. While oil or paraffin treatments have historically been used to “set” dyes in stones like jade, lapis lazuli, and amazonite, the beads in question were not dyed, and the reason for oiling alone remains unclear—possibly done to mask a poor polish.

gems, ancient gemology, early gemology, ancient mineralogy, early trade, glyptic

The following studies serve as the archaeological foundation for a history of craft and technology in ancient Mesopotamia, though they are not intended as an attempt to write that history. The goal has been to provide what Leo Oppenheim called a “systematic and critical inventory of the technological achievements of Mesopotamian civilization” in areas such as metalwork, glazed materials, and glass, as a preliminary step toward broader surveys. Integrating this material with the relevant documentary evidence to understand the wider socio-economic environment in which these technologies developed and thrived—a necessary framework for any true history of technology—is a task of a wholly different scale. With few exceptions, the data on material culture and documentary sources from Mesopotamia remain only partially published, scattered, and often accessible only to specialists. Even in Classical Studies, where the documentation is far richer and more thoroughly examined, the history of technology has until recently held a relatively low academic status, likely due to a persistent tendency to treat the subject in isolation, divorced from its social context and economic processes.

corundum, quality.10, gems, Indian lapidary

Naveen Patnaik’s A Second Paradise: Indian Courtly Life 1590–1947, with an introduction by Stuart Cary Welch and illustrations by Bannu (Ved Pal Sharma), presents an illustrated account of the splendor, customs, artistic patronage, and ceremonial traditions of India’s princely courts from the Mughal period to independence in 1947. Published in association with the Metropolitan Museum of Art and the 1985 Festival of India, the book combines historical narrative, Mughal and Rajput miniature paintings, early photographs, and contemporary illustrations to reconstruct the material and cultural world of Indian rulers. Jacqueline Kennedy Onassis served as editor, while Welch contributes an introduction examining Indian painting and the development of Mughal, Rajput, and British-period artistic traditions. Patnaik’s narrative describes the education of princes, court ceremonies, royal processions, marriages, festivals, hunting, music, dance, architecture, clothing, and the elaborate etiquette governing the lives of maharajas, nawabs, begums, and courtesans. Gemstones and jewelry figure prominently as symbols of sovereignty, wealth, divine favor, and personal adornment. Indian rulers wore elaborate necklaces, jeweled armbands, anklets, rings, and turban ornaments, including the sarpej, while royal horses and elephants were adorned with gold and precious stones. Particular attention is given to the navaratna tradition, in which nine gemstones represented the celestial bodies and were believed to confer auspicious planetary influences. Rubies were associated with the sun and sapphires with Saturn, illustrating the intersection of gemology, astrology, and royal ceremonial practice. The book discusses India’s historical gemstone sources, including the diamond mines of Golconda, Kashmir sapphires, Burmese rubies, and pearls from the Persian Gulf, while also mentioning emeralds associated with Tonk. The Koh-i-Noor diamond receives attention through the account of its seizure by Nadir Shah and its subsequent acquisition by the British following the annexation of Punjab. Maharaja Duleep Singh’s dispossession and exile provide a particularly revealing example of how exceptional gemstones became symbols of political conquest and imperial authority. The Mughal court of Shah Jahan is portrayed as a center of extraordinary luxury, with the jewel-encrusted Peacock Throne, ceremonial daggers with carved jade and gemstone handles, and architectural decoration incorporating colored stones. The bazaars of Shahjahanabad contained workshops of goldsmiths and jewelers, alongside merchants selling carved jade, ivory, textiles, and other luxury goods. The author also describes the use of Chinese jade vessels as supposed detectors of poison, reflecting historical beliefs concerning the protective properties of precious materials. Traditional miniature painting techniques receive detailed treatment in Welch’s account of Bannu’s workshop, including the preparation of mineral pigments, the use of agate burnishers, and the application of powdered gold to create jewel-like surfaces. The illustrated sections reproduce court portraits and scenes of elaborate dress, documenting changes in jewelry fashions from Mughal and Rajput traditions to the European-influenced styles of the British period. During the late nineteenth and early twentieth centuries, Indian princes increasingly patronized European jewelers, notably Cartier, replacing some traditional enamel settings with Western designs and incorporating gemstones acquired through international trade. The volume concludes with the decline of princely authority under British rule and the dissolution of the princely states following independence. For gemologists and jewelry historians, the book provides valuable visual and historical evidence of gemstone use, royal ornamentation, traditional jewel-setting practices, the symbolic significance of precious stones, and the transformation of Indian courtly jewelry over more than three centuries.

corundum, synthetic corundum.7, gems

A 2.35 ct faceted sapphire is described in which conspicuous polysynthetic twin lamellae closely resembled those commonly associated with natural corundum, although further examination established a Verneuil synthetic origin. The stone’s unusually intense colour initially raised suspicion of treatment, but colour alone was considered unreliable for distinguishing natural from synthetic sapphire. Examination with a 10× lens revealed a few straight, parallel twinning lines in an otherwise particularly clean stone. The girdle lacked the pockmarked appearance sometimes associated with heating, while immersion in methylene iodide suggested that colour was concentrated near the surface. The iron absorption line near 450 nm was absent, and the stone remained inert under both long-wave and short-wave ultraviolet radiation. Immersion microscopy between crossed polarisers readily revealed the straight twin lamellae, including interference rings along the twin planes. Because such twinning can occur exceptionally in Verneuil corundum, its presence was not accepted as conclusive evidence of natural origin. Examination along the optic axis under crossed polarisers produced the characteristic Plato striation pattern, described as a lozenge-shaped arrangement formed by intersecting sets of lamellae. Curved colour bands, further supporting the Verneuil identification, were difficult to observe and became visible only during immersion with illumination diffused through tissue paper. The author distinguishes the conspicuous polysynthetic lamellae from the structures responsible for the Plato pattern because they followed different directions. The former appeared to lie in planes slightly inclined to the optic axis, but their precise crystallographic orientation could not be established from the faceted specimen. Although all Verneuil synthetics previously examined by the author had yielded a positive Plato test, this was the only sapphire encountered with such convincing natural-like polysynthetic twinning. The report therefore stresses the importance of seeking curved colour banding or Plato striations before identifying a sapphire from twinning alone. Possible surface diffusion treatment is also discussed because of the apparent surface concentration of colour and the absence of the usual chalky bluish green short-wave fluorescence. This interpretation remained tentative, since the stone could not be tested by repolishing. The case demonstrates how an unusual combination of internal structures and possible treatment effects can complicate sapphire identification.