gems, jade, yu, fei cui, nephrite, jadeite, China, Burma, Myanmar, New Zealand, Canada, USA, Japan, Russia, Korea

Sinkankas: Jade as a mineral, p l–14 (with F W Clarke, on jade colors, 6–10); SL Penfield, crystalline system, optical properties, 14–17; C Palache, properties & table, 17–36; JP Iddings, microscopic petrography, 37–60; tenacity, 60–62; L W Page, impact tests, 62–70; I H Woolson, compression & tension tests, 70–93, 93–95; fracture, hardness, 95–98; TA Jaggar, microsclerometer hardness tests, 98–110; W Hallock, SG, 111–15; sonorousness, 116–9; W Hallock, sonorousness tests, 120–4; F W Clarke, chemical constitution, 125–77; S L Penfield, chemical notes, 177–96; inclusions, 197–99; L V Pirsson, origin of jadeite, 200–7; JP Iddings, relation of jadeite to nephrite, 208–12; HS Washington, localities, geol occurrences, 213–64; G F Kunz, minerals mistaken for, 265–84; S W Bushell, jade in China, 285–320, also by Bushell: Yii-Shuo, a discourse on jade ... by T'ang Jung-Tso styled Hsi-Wu ... translated by Stephen W Bushell, p 321–66, with an appendix giving titles of 71 books quoted in the discourse, p 367–70, and illustrations of the modem manu- facture of jade... by Li Shih-Ch'iian, styled Cheng-Yuan, p 371–78 [actually descriptions of the illustrations and not the illustrations themselves, which are not given here]. Because of its importance, this contribution is described separately, see T'ANG JUNG-TSO.Aside from the detailed work on jades by H Fischer (l880), which see, no other work, even now, approaches the above for its wealth of property data; the occurrences section by Washington is richly supplied with bibliographical footnotes of continuing value to students of jades. Bushell's translation seems to be found nowhere else save here. This book, apparently printed in very few copies and probably for extremely limited private circulation is so rare that I have not seen advertised another copy in thirty years.

ruby, sapphire, corundum, Burma.12, geology.11, gems

Brown and Judd present a detailed investigation of the ruby deposits of Burma, based on geological observations and specimens collected by Brown and mineralogical and petrographic examination by Judd. They describe the occurrence of ruby at Mogok and neighboring localities, emphasizing its association with crystalline limestone and the minerals accompanying it, and distinguish primary occurrences from the secondary gem-bearing deposits produced by weathering and erosion. Microscopic study is used to investigate the structure of corundum and the numerous inclusions, alterations, and secondary minerals developed within or around the crystals. Particular attention is given to the transformation of corundum into other minerals and to the evidence these changes provide concerning the geological history of the ruby-bearing rocks. The authors discuss the probable origin of Burmese ruby, the metamorphic processes affecting the deposits, and the subsequent concentration of resistant corundum crystals in superficial deposits. The paper is an important early study combining field geology, mineralogy, and petrography to explain the occurrence, origin, and alteration of the rubies of the Mogok district.

corundum, history.1, gems, Arabic mineralogy, ancient gemology, history of gemology, antique gems, glyptic, early lapidaries

As one progresses in the study of lapidaries, one becomes convinced that they all stem from a common source; but so far, that source has not yet emerged from the obscurity surrounding its origins. In all these treatises, in fact, we find the same legends, the same myths. Whether it concerns lapidaries of precious stones or lapidaries of engraved stones, lapidaries from Antiquity or from the late Middle Ages, whichever manuscript we turn to, whichever author we consult, we always encounter the same fables: they vary only in form, never in substance. To uncover this original source, it would seem at first glance that one need only go back, continually retracing the chain we possess, and that the oldest known lapidary must, in some sense, be the original treatise. That would be a great error. The path is strewn with pitfalls, full of unforeseen twists and turns; just when one believes one firmly holds the guiding thread through this labyrinth, it suddenly breaks, and acquisitions that once seemed definitive abruptly vanish, leaving in their place a new field of exploration where everything must be rediscovered. In this realm of legend, where each century has left something of itself, imagination sometimes takes hold and one believes one can intuit meanings; yet on the contrary, in these scientific and magical treatises, there exists a tradition that has been faithfully transmitted and which one finds absolutely identical at both ends of the historical spectrum. The most precise method, the most scrupulous criticism, are thus essential here: they must accompany every step forward with their checks and allow the inclusion of a document in the general structure of the work only insofar as it appears absolutely indisputable. As of today, one point is absolutely established: it can serve as a reliable foundation. All known lapidaries, whether manuscript or printed, derive from one of the following four origins: 1° Greek: represented by Theophrastus, Dioscorides, the Cyranides, Hermes, Damigeron, the Book of Enoch, the Μετὰ Ζῆλος of Orpheus, the Pseudo-Plutarch, and Psellus. 2° Latin: preserved for us by Pliny, Saint Isidore, and Marbode; this tradition does not appear to have been interrupted in the West. 3° Arabic: the Book of Stones of Aristotle, the Book of Talismans, al-Bīrūnī, Ibn al-Bayṭār, and al-Tīfāshī seem to encapsulate the knowledge of Eastern lapidaries. 4° Hebrew: which certainly shows the greatest affinities with the Arabic lapidaries, but of which we also find absolutely distinctive traces in the Western lapidaries that we possess.

corundum, inclusions.5, gems, spinel, inclusions

Prinz examines microscopic inclusions in sapphire, ruby, and spinel, describing the internal features observed in specimens of these gemstones and illustrating them on an accompanying plate. He discusses the form, distribution, and appearance of the inclusions under magnification and considers their possible nature and origin. The paper is an early application of microscopy to the systematic examination of gemstone inclusions and is particularly significant to gemology because such internal features later became important criteria for identifying gems, determining their natural origin, and distinguishing between closely similar materials.

gems, inclusions, quartz

Sinkankas: In a masterful introduction to the study of inclusions in crystallized minerals, the authors set forth the fundamental principles of paragenesis and the evidence supporting them, considering types of inclusions based on environment and genesis type, such as whether the minerals were grown from solution or in an igneous rock mass. The first part provides 334 examples of inclusions, followed by a table of 107 others, a table of chemical groups into which the minerals containing inclusions fall, and copious notes. In the second part, the authors begin with a brief historical survey of the knowledge of inclusions, mentioning Claudian to show that the ancients were already aware of watery inclusions in rock crystal, and naming mineralogists and collectors thereafter, especially in the latter half of the 18th century, who remarked on or zealously collected inclusions, regardless of cost. Notable authorities such as Pini, Collini, Davila, Rome Delisle, Reuss, Jameson, and others are featured. The text of this part starts with quartz, with no less than 43 examples of inclusions in rock crystal, amethyst, etc., followed by 13 in calcite and numerous others in fluorite, barite, topaz, tourmaline, adularia, beryl, analcime, apophyllite, and more. The second part concludes with a handsome colored plate of inclusions and phantoms in quartz, calcite, and fluorite. The third part begins with a further discussion and a list of periodicals the authors consulted. This is followed by examples of microscopic or “cryptic” inclusions, such as sunstone and bronzite, as well as a brief note on diamond, in which the “ashes of burnt diamonds showed traces of organic structure,” along with several examples of phantom growth and explanations of inclusion growth in minerals like tourmaline, cakite, aragonite, garnet, fluorite, and others. While this is the first systematic monograph to describe and offer paragenetic theories on the growth of inclusions, it does not mention the work of David Brewster of Scotland, who published important discoveries in his Edinburgh Philosophical Journal from 1823 onward, especially recognizing two- and three-phase inclusions in topaz. See also SOCHTING, J.W.E., 1860.

gems, lapidary, gem cutting, France, Jura mountains, diamond cutting, jade, Fischer-Book

Sinkankas: A large, detailed work which embraces not only gemstones but also ornamental and monumental kinds, with much on their extraction, working, and polishing. First volume: gemstones, ornamental stones, with discussion of crystallography, mineral properties, detailed descriptions of hard" and "soft" stones, with diamond receiving most attention; others treated include corundum, chrysoberyl, spine!, topaz, beryl, zircon, garnet, euclase, quartz, the last also given a great deal of space for its treatment of crystalline & cryptocrystalline varieties (p 79-149), and including opal, a large number of trivial jasper varieties, and, briefly, descriptions of figured stones, natural and false, engraved gems, etc. Among "soft" stones are idocrase, peridot, tourmaline, epidote, kyanite, prehnite, feldspars (including jade which Brard believes to be a kind of compact feldspar), hypersthene, lapis lazuli, lepidolite, natrolite, chiastolite, fluorite, calcite, talc and gypsum. This section is quite remarkable for its treatment of so many uncommon or rare gemstones and is one of the earliest treatises to include many of them. In an appendix to the first volume, Brard also treats halite, jet, hard coal, amber, malachite, turquoise, pyrite, hematite, rhodonite and obsidian although there seems to be no explanation why these materials were separately treated. Here also appears a very brief remark on magnetite and "eagle-stone" amulets, followed by a short discus- sion on how to detect differences between real and false gems, among the interesting remarks being Brard's recognition of spherical inclusions as being typical of glasses rather than of real gemstones (p 209). Volume I closes with a good explanation of lapidary techniques and abrasive/polishing agents, and the "agate mills" of ldar-Oberstein, Pl IV. The engraved plates additionally depict crystal forms, a lapidary bench as used in Paris, wire saw, diamond cuts, disk saw, carving tools, a multiple-blade saw, a lapidary in the act of sawing, and a gem-engraver's bench with accessories. In contrast, the second volume is far less interesting to the gemologist inasmuch as it confines itself to monumen- tal/architectural stones, eg, porphyries, variolites, amygdaloids, granites,etc, while others are the numerous varieties of marbles and alabasters, along with explanations of quarrying and process- ing of stones into finished shapes. A scarce and important work giving every evidence of great care in selecting and assembling accurate and useful information, reflecting the state of the stone arts at that time."

gems, corundum, history.1, jade, Fischer, beryl, emerald, opal, turquoise, jasper, malachite, treatments, simulants, lore

The Roman author and historian Gaius Plinius Secundus, a.k.a. Pliny the Elder (23-79 A.D.) compiled the Naturalis Historia (Natural History) from a reported two thousand sources. This thirty-seven volume work, published in 77A.D., embraces the domain of natural history in the broadest sense. It includes astronomy, geography and meteorology. Beyond what is today considered natural history, it also includes fine arts, inventions, and human relations. It stands as the chief source from which future historians have obtained informative descriptions of life in the first century. Much of Pliny’s information on gems was not written from direct observation. His studies were often a retelling from second-hand sources, now lost in antiquity. Many stones are lumped together by color, mining location, or attributes passed on in legends. His recounting of legends and myths, and assumptions drawn from these, are the basis of much of the writing which appeared into the Middle Ages. He became the most often quoted writer on the subject, and his information was relied upon and repeated without question in book after book. In the first thirteen centuries of European history, little scientific in-formation was added to the limited knowledge of gems garnered from Pliny’s accounts. However, many later authors embellished the writings and added their own speculations and unwarranted conclusions. Pliny is credited with his attempts to classify gems according to color and observable external characteristics. This led to the practice of assigning the attributes of one stone to all stones of similar color or appearance. The green stones named smaragdus in Latin are prime examples. Pliny classified most green stones as varieties of emerald. In all, twelve varieties are listed; green sapphire, turquoise, smithsonite, malachite, jasper, and even glass are identifiable by his descriptions. He also is credited with making some astute classifications. It is thought that he was the first to recognize the connection between beryls and emeralds. Some of the stones grouped by Pliny share little in common. It is obvious that some of his “observations” were gathered through other’s eyes. Errors in translation or reliance on oral tradition may have led to the inclusion of misinformation about stones that Pliny was not able to observe in nature. Since the original Latin version, over two hundred and fifty editions of his classic have been published in numerous languages. The first complete edition of Natural History was published in Venice in 1469, and the first critical edition was offered by Hardouin in 1685. The most detailed study of Pliny’s gemstone accounts is a work by S. H. Ball. See also the translations from Eichholz, which many experts consider more authoritative.

gems, corundum, sapphire, vesuvianite

The author recently examined a sapphire containing an elongated, rod-shaped crystal associated with a partially healed fissure (figure 8). Due to its morphology and color, the inclusion appeared to be pargasite. However, subsequent analysis using Raman spectroscopy identified the inclusion as vesuvianite. Vesuvianite is an accessory sorosilicate mineral that typically forms in skarn during metasomatism of carbonate rocks such as limestone. Exceptionally rare as an inclusion in gemstones, vesuvianite has previously only been documented in two rubies from Mogok, Myanmar (Winter 2017 G&G Micro-World, p. 469; C.P. Smith and R. Zellagui, “Vesuvianite (idocrase) and apatite inclusions in ruby identifiable by infrared spectroscopy,” Journal of Gemmology, Vol. 37, No. 4, 2020, pp. 346–348). Given the association of vesuvianite with skarns, these inclusions may also occur in sapphires from skarn deposits, such as those in Andranondambo, Madagascar, and Kataragama and Elahera, Sri Lanka (G. Giuliani and L.A. Groat, “Geology of corundum and emerald gem deposits: A review,” Winter 2019 G&G, pp. 464–489). To the author’s knowledge, this is the first report of vesuvianite as an inclusion in sapphire.

gems, jade, fei cui, pyroxene jade, Guatemala, jadeite, omphacite, lavender jade, black jade

This study systematically investigates the mineralogical, spectral, and geochemical characteristics of Guatemalan lavender jadeite and black omphacite to elucidate their coloration mechanisms and genetic origins. Lavender samples are primarily composed of jadeite, which derives its color from synergistic effects involving Mn³⁺ and Fe²⁺–Ti⁴⁺ charge transfer (554–614 nm). In contrast, black samples are dominated by omphacite, which owes its dark hue to Cr³⁺ (670 nm) and Fe²⁺–Fe³⁺ charge transfer (857 nm). Chemically, lavender jadeite exhibits higher Na₂O and Al₂O₃, approaching the jadeite end-member composition, whereas black omphacite is enriched in CaO, MgO, and FeO. Trace element analyses reveal low overall abundances, with black omphacite showing synchronous LREE and HREE depletion forming a “bulge-shaped” pattern, while lavender jadeite displays N‑MORB‑like REE distributions. Guatemalan jadeites are distinguished from Myanmar counterparts by Y enrichment. The identification of graphite and CH₄ and CO₂ fluid inclusions indicates formation in an organic-rich reducing environment. Cathodoluminescence zoning and abundant fluid inclusions support a direct crystallization genesis from high-pressure fluids (P‑type) in subduction zones. This study establishes key constraints for origin discrimination and genetic classification of Guatemalan lavender jadeite and black omphacite.

gems, corundum, inclusions.5, basalt sapphire

The authors recently examined a 1.80 ct greenish blue sapphire and were surprised to observe a dark red internal protuberance jutting inward from the surface of the pavilion (figure 8). The prismatic inclusion was identified as manganotantalite ((Mn,Fe)(Ta₂O₆); a manganese-enriched iron-tantalum oxide) using Raman spectroscopy, consistent with its red bodycolor. This mineral displayed a blunt termination and etched pinacoidal surfaces. Laser ablation–inductively coupled plasma–mass spectrometry analysis showed that the host sapphire had iron levels of up to 1900 ppma. With a spectroscope, a strong broad absorption around 840–880 nm was observed. These observations are consistent with known occurrences of tantalite in sapphire hosts from basaltic-related origins (S. Promwongnan and C. Sutthirat, “Mineral inclusions in ruby and sapphire from the Bo Welu gem deposit in Chanthaburi, Thailand,” Fall 2019 G&G, [354–369]). While tantalite itself is not uncommon in sapphires of this type, this inclusion was notable due to its interesting morphology and attractive dark red color, attributed to the presence of manganese, which contrasted with the greenish blue stone (O.I. Lee and E.T. Wherry, “Manganotantalite from Amelia, Virginia,” American Mineralogist, Vol. 4, No. 7, 1919, [80–83]).