gems, ancient gemology, Theophrastus, bibliography, early mineralogy, early lapidaries

No systematic study of the manuscripts of Theophrastus has ever been attempted, though a worthy effort was made by the Leipzig editors of the Characters. As the number of existing manuscripts, both of the Characters and the other works, far exceeds the number of those already known and collated, the present list may be useful. My list comes from the catalogues mentioned in M. Richard, Répertoire des Bibliothèques et des Catalogues des MSS. Grecs, 2nd ed., Paris 1958. Not all the catalogues are accessible to me, and though Richard makes it clear that the majority of those do not contain any classical manuscripts, there are still some that I should have liked to consult. They are (by Richard’s numbers): 93, 172, 325, 441, 477, 505, 509. This list consists in fact mostly of minor libraries in various Balkan towns, and as such libraries are rarely of importance, it is not likely that much of interest could be added from them. At this point I should say that I am much indebted to M. M. Wittek for his kindness in securing for me some inaccessible catalogues. The data given about each manuscript come from the catalogues, but in many cases have been supplemented by my own inspection of a manuscript. A few lost collections of manuscripts I have not bothered to investigate very closely. I have departed from the usual practice in such lists of the manuscripts of one author by adding sections on papyri, indirect tradition (on the Characters only), scholia, and translations into Latin, Oriental, and modern vernacular languages.

gems, ancient gemology, early gemology, ancient mineralogy, early trade, Rome, Romans, Greeks, ancient trade, commerce, cuprorivate, Italy

Cuprorivaite was first described as a new mineral from Vesuvius by Minguzzi in 1938, who proposed the formula 2(Ca, Na)(Cu, Al)(Si, Al)₂(O, OH)₁₀·H₂O, based on analyses of impure material with adjustments for contamination. However, the validity of the species has been debated; Strunz (1957, p. 366), for instance, argued that cuprorivaite is merely a mixture of wollastonite and glass. One of the present authors, Pabst (1959), proposed instead that cuprorivaite is likely the natural analogue of Egyptian blue, CaCuSi₄O₁₀. A reexamination was conducted using crushed material from the original type specimen described by Minguzzi, as no other confirmed samples of cuprorivaite were available for further study.

corundum, fashioning.9, synthetic corundum.7, gems

Eppler examines crack-like surface markings on polished corundum, commonly called fire marks or chatter marks, and challenges their widespread use as evidence of synthetic origin. Although frequently observed on synthetic ruby and sapphire, these features also occur on natural corundum and therefore cannot independently distinguish natural from laboratory-grown stones. The article reinforces Gübelin’s earlier warning that such markings reflect polishing conditions, while noting that this qualification had received insufficient attention in gemmological literature and teaching. Photomicrographs compare markings on synthetic sapphire with examples on natural sapphires of different colours and geographical origins, including sapphires from Ceylon and a greenish-blue Australian specimen. A rose-coloured Ceylon sapphire displays both surface fire marks and a healing fissure composed of small liquid inclusions. Images of chatter marks on turned steel illustrate the resemblance responsible for the alternative terminology. In metalworking, these patterns arise through displacement and overlapping of material associated with vibration, excessive loading, unsuitable turning speeds, or other operating conditions; the comparison establishes a morphological resemblance rather than an identical mechanism of formation. Eppler emphasizes the parallel arrangement of the corundum markings and their corresponding segments, together with characteristic angular relationships. Some examples show angles approaching ninety degrees, whereas others approach 120 degrees. Their appearance ranges from broad marks to fine fissure-like lines. A higher-magnification view of an Australian sapphire shows a marking continuing beneath the polished surface, supporting its interpretation as a wedge-shaped crack rather than a purely superficial blemish. Accepting excessively rapid polishing or localized overheating as the initiating cause, Eppler proposes that localized stress produces parting along planes of the primitive rhombohedron. The orientation of each polished facet relative to these crystallographic planes would then determine the directions, shapes, and angles of the resulting fissures, accounting for their varied appearance. He extends the same explanation to comparable markings on natural ruby. The article’s principal contribution is an illustrated correction to a misleading identification criterion: fire marks are polishing-related features of corundum that can occur in both natural and synthetic material, and their presence must not be treated as conclusive evidence of synthetic manufacture.

gems, Brazil, emerald, topaz, quartz

Review of the gem deposits of Brazil.

gems, ekanite, Ceylon, Sri Lanka

Sinkankas: Tentatively a calcium thorium silicate from the gem gravels of Ceylon, named after F. L. D. Ekanayake, who first drew attention to its remarkable properties. Essentially the same article was repeated in Zeitschrift der Deutschen Gesellschaft für Edelsteinkunde, 40, 1962, p. 29, and in The Gemmologist, 31, 1962, pp. 142–152, 165–169, 16 figures; not seen. Mineralogical Abstracts, 16(4), p. 358.

corundum, synthetic corundum.7, assembled stones, gems

F.H. Pough examines newly marketed assembled star stones, comparing their construction, appearance, identification, and durability with earlier attempts to imitate natural star rubies and sapphires. He traces the development from fixed stars engraved on the backs of glass or synthetic gemstones to more convincing moving-star effects obtained from coated star quartz, scratched synthetic corundum, and phlogopite-backed composites. These predecessors demonstrate that movement of a star with viewing angle cannot by itself establish natural origin. Earlier products often suffered from weak optical effects, excessively deep cabochons, unstable coatings, or adhesives that separated during wear. The introduction of epoxy resins revived interest in assembled stones by providing stronger, water-resistant bonds. Pough describes two contemporary constructions employing shallow cabochon tops, principally synthetic corundum or spinel, although glass is also used. In the first, a transparent top is cemented to thin glass backing apparently scratched in one direction for a cat’s-eye or three directions for a star, then coated with a reflective metallic film. The shallow top improves light return, producing a brighter effect than earlier high-domed versions, although the reflected star is more strongly coloured than those of natural or Linde synthetic star stones. The second construction joins a synthetic ruby or sapphire top to an opaque, deeply coloured sintered-corundum backing with a metallic solder layer. Pough infers that microscopic grooves on the underside of the top generate the star, while the solder both bonds the components and supplies the reflecting surface. X-ray examination supports identification of the tested red backing as corundum. This construction produces particularly sharp, bright stars and appears somewhat more resistant to extreme conditions than the epoxy-bonded glass-backed version. Both products nevertheless separate or suffer damage under sufficiently severe heating, although Pough considers ordinary wear unlikely to reproduce those conditions. Recognition is straightforward when the stones are loose, and the unusually dark sintered backing remains a useful clue in mounted examples. He distinguishes three possible locations for the star-producing structures: within the gemstone, on its underside, or in an attached backing. The new products receive qualified approval for beauty and apparent durability, but Pough predicts that their ease of manufacture and competition from poorer glass versions may undermine their commercial appeal.

synthetic corundum.7, hydrothermal, gems

Gübelin investigates two recently introduced gem products—rubies represented as hydrothermally grown and natural beryl coated with synthetic emerald—emphasizing the identification difficulties created when synthetic growth surrounds a natural crystal containing convincing natural inclusions. He first reviews the hydrothermal synthesis of corundum developed by Laudise and Ballman at Bell Telephone Laboratories, describing the transport of dissolved nutrient through a temperature gradient in a pressurized vessel and its deposition on suspended seed crystals. Chromium supplies the ruby colour, while growth conditions and the materials used in the apparatus influence the resulting crystals. The ruby specimens personally examined, claimed to originate from Chatham, consisted predominantly of natural ruby cores covered by relatively thin synthetic layers. Their refractive indices, birefringence, specific gravity, dichroism, absorption spectra, and fluorescence provided no reliable separation from natural ruby. The cores contained rutile silk, mineral inclusions, and liquid feathers, while the overgrowth reproduced the original crystals’ external forms. Identification depended on minute features interpreted as gas bubbles within the surface layer, occurring singly or in lines, clouds, and planes, together with the abrupt termination of natural inclusions at the boundary between core and overgrowth. Gübelin notes that ordinary cutting could remove most or all of these thin coatings. The second product, manufactured by Johann Lechleitner and marketed as Emerita, comprised a previously fashioned natural beryl nucleus overgrown with a thin hydrothermal synthetic emerald mantle. The coating continued the crystallographic orientation of the seed, forming a continuous crystal rather than a cemented assembly. Its thickness varied with crystallographic direction and controlled the apparent colour. Standard gemmological properties again overlapped those of natural emerald, and refractometer readings primarily represented the synthetic surface. Microscopy, particularly with immersion and examination from the side, revealed the dark green rim around a pale or colourless core, occasional reflections at the interface, and characteristic structures within the overgrowth. These included parallel or intersecting tension fractures, partly healed fissures containing residual liquid droplets, and particles provisionally interpreted as other mineral phases, such as phenakite or euclase. Some particles obstructed growth and produced tapering cavities containing liquid and a bubble. High magnification and phase contrast helped clarify these delicate features and their relationship to the growth process. Gübelin concludes that natural inclusions within a seed cannot establish the natural origin of the entire stone. Careful examination must instead distinguish the core from its synthetic mantle. He also stresses that altered manufacturing conditions can eliminate many diagnostic inclusions; in exceptionally clean emerald coatings, the contrast between the green outer layer and pale interior may provide the only decisive evidence.

gems, ancient gemology, early gemology, ancient mineralogy, early trade, India

Indus Valley trade in the 3rd millennium B.C. Draws upon the literary reference Jatakas.

gems, ancient gemology, early gemology, ancient mineralogy, early trade, India

In the complex economic structure of medieval South India, guilds played a vital role in the growth of trade and industry. They not only engaged in the exchange of various commodities and accumulated substantial profits but also contributed significantly to the state’s revenue, often providing crucial support to the ruling powers. While this dual function was typical of guilds throughout history, what stands out in the South Indian context is their autonomy and influence—they maintained their own militias and exercised considerable freedom in recovering dues from clients, often with the full approval of the feudal lords.

gems, ancient gemology, early gemology, ancient mineralogy, early trade, India

In ancient India, the love for ornaments was deeply rooted in society, and those who crafted them—jewellers and goldsmiths—held positions of high regard. Celebrated for their refined craftsmanship and aesthetic sensibility, Indian artisans, particularly the suvarnakaras (goldsmiths), enjoyed a respected status, with their work receiving wide appreciation. Kauṭilya’s Arthaśāstra highlights the importance of these craftsmen, noting qualities such as good family background, skill, and conduct. This study offers a broad survey of the ornament industry in India from the 6th century B.C. to the 3rd century A.D., drawing on literary sources including the Jatakas, Panini, Kauṭilya, Patanjali, and Hāla, alongside archaeological evidence from Taxila, to explore the nature and techniques of early Indian ornament production.