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The book of hours examined for this study is an illuminated Renaissance masterpiece: a small prayer book bound in enamelled gold and gemstones that was bought in 1538 by King Francis I of France as a probable gift for his niece. In 2018, it was acquired by the Louvre Museum (Paris, France) from S. J. Phillips Ltd in London, and its nearly complete history is documented here. A first gemmological analysis of the stones adorning the book was conducted on site at the Louvre in 2020. The gems consist of carnelian (two intaglios and eight cameos), rubies (27 polished pieces), turquoise (24 cabochons) and rhodolite (one faceted stone in the book's clasp that has been described as tourmaline since 1942). We suggest that most of the rubies were mined from the Mogok area of Burma (now Myanmar). Based on historical considerations, the turquoise could have originated from Persia or possibly Uzbekistan, and the carnelian from either India or Saxony. The faceted rhodolite could have originated from India or Sri Lanka, and was most likely added to the clasp in more recent times, possibly between 1842 and 1884. [ABSTRACT FROM AUTHOR]

The article titled "Determination of Common and Rare Gemstones with a Dichotomy Approach" by Yves Lulsac provides a handbook for gemmologists to identify a wide range of common and rare gem materials. Originally written in French, the book has been translated into English by gemmologist Blanca Mocquet. The book follows a process of elimination to identify gem materials based on accurate measurement of optical properties and other characteristics. While the book does not replace standard works on gemmology, it offers a unique approach to gem testing and is a useful aid for practicing gemmologists. [Extracted from the article]

The Hornby diamond has received scant attention in the literature on gems, with writers noting merely that it was supposedly sold to a shah in Persia in the early 1800s. Detailed information about this diamond is available, however, in a book written by the British diplomat Sir Harford Jones Brydges in the 1830s. From this and other documentation it possible to pick up the trail of this ~60 ct pink diamond, proceeding from the Iranian Shah Karim Khan to India and then to Britain, where it was put up for auction, and finally back to the Iranian court where, as a diplomatic gift, it helped thwart Napoleon's plans to invade British India. If this diamond still resides within the Iranian Crown jewels, it seems possible that it the pink Nur al-'Ayn ('Light of the Eye'), which is estimated to weigh approximately 60 ct. [ABSTRACT FROM AUTHOR]

Our knowledge of the history of the French Blue/Hope diamond between the time of its theft from the French Crown Jewels in 1792 and its publication as part of the collection of Henry Philip Hope in 1839 has many tantalising gaps. Based on new research, this article covers what we now know of this diamond after its reappearance in London in 1812. A painting of the diamond by the mineralogist James Sowerby has been located, along with Sowerby's notes. These formed the basis for an advertising pamphlet for the gem produced by London jeweller Daniel Eliason, published in English and French versions, which can now be dated to 1813. We also learn that Eliason and Sowerby exhibited, or at least planned to exhibit, a blue glass model of the diamond at the Linnean Society in London. Several sources point to 1821 as being the year Henry Philip Hope purchased the diamond in London. The testimonies in the 1840s court cases surrounding the ownership of Hope's gem collection following his death in 1839 provide useful background information and, remarkably, suggest that in 1838 there was an attempt to sell the diamond back to the French Crown. [ABSTRACT FROM AUTHOR]

The article offers information on the petroleum inclusions found at the pink spinel examined by the American Gemological Laboratories.

Glass simulants of gemstones were long produced with little or no prejudice against their use. However, their making is poorly documented due to the secretiveness imposed by glassmaking guilds, despite the presence of some late medieval manuscripts that have recently appeared. They reveal glass composition and fabrication recipes in accordance with the trend launched by 16th-century 'writers of secrets', who revealed technological developments to the public. Giovan Battista Della Porta was the first to publish in print recipes for making glass simulants of gems, in addition to information on the enhancement of natural gem materials. His Magiae Naturalis (1558), originally written in Latin to appeal to upper-class amateurs, enjoyed vernacular translations in several European languages. The second, vastly improved edition (Della Porta, 1589), again in Latin, did not enjoy the same popularity-- possibly because the first one had saturated the market or, alternatively, because the Catholic Church had enforced rules that made alchemy a forbidden practice, and even the title Magiae became suspect. In spite of such restrictions, both editions contributed to making glass 'gems' popular decorative objects and to increasing their trade. During Baroque times, interest in glass 'gem' making reached an acme, and Della Porta's treatise was even translated into English in 1658. [ABSTRACT FROM AUTHOR]

The proliferation of gemmological laboratory reports and the need for transparency to best protect against litigation suggest that some gem-testing laboratories should consider changes in the wording and content of their geographical origin reports. Based on the author's recent broader study of the legal aspects of the opinions provided by experts in the field of art and antiques, the main proposals presented here are that statements of opinion rather than fact should be clearly expressed as such where they are presented on a report, rather than relegating all mention of 'opinion' to the 'terms and conditions', and that the basic nature of the observational or analytical evidence on which any opinions are based should be noted. In addition, a laboratory might usefully provide some indication of the level of confidence in its opinion. [ABSTRACT FROM AUTHOR]

A response on a letter to the editor on the article regarding the photo in the summary on inclusions in cat's-eye, star and other chrysoberyls that appeared in the May/June 2016 issue of the journal is presented.

A letter to the editor and a reply is presented in response to the article regarding the photo in the summary on inclusions in cat's-eye, star and other chrysoberyls that appeared in the May/June 2016 issue of the journal.

The article discusses the 35th International Geological Congress at Cape Town in South Africa on August 27, 2016 to September 4, 2016 with programme consisting of several presentations which include the session entitled "Gems: Bringing the World Together".

In September 2015, a 1.75 ct pink sapphire was submitted to the Gem and Jewelry Institute of Thailand's Gem Testing Laboratory (GIT-GTL). The stone showed internal features (e.g. flash effects and trapped gas bubbles) that are commonly seen in lead-glass-filled rubies and sapphires. In addition, the sample turned out to be an assembled stone, consisting of a pink sapphire crown and a near-colourless sapphire pavilion. These two portions were joined along a lead-glass-filled contact layer slightly below the girdle that locally contained areas of corundum fragments. We concluded that this stone was a lead-glass-filled corundum doublet. [ABSTRACT FROM AUTHOR]

One of the most famous stones mentioned in the gemmological literature is the so-called Great Mughal diamond, described and depicted in a 17th-century work of Jean-Baptiste Tavernier. According to Tavernier, this specimen weighed ~286 metric carats (upon recalculation from Eastern units); it was not mentioned in later sources referring to the Mughal court. In the 18th century, however, a diamond reminiscent of the Great Mughal appeared on the market--it is known today as the Orlov (189.62 ct). Some researchers have suggested that these specimens could be identical, if not for the fact that the Orlov weighs about 90 ct less than the stone reported by Tavernier. This discrepancy may be explained by the inference that Tavernier never actually examined the stone, but he only described it from accounts given by others. This deduction, together with new evidence showing that the stone actually weighed ~193.5 ct, indicates a high likelihood that the Great Mughal is the same as the Orlov diamond. [ABSTRACT FROM AUTHOR]

Milky-appearing alexandrite samples from Tanzania (Lake Manyara) and India (Kerala) were examined, as were chatoyant and asteriated chrysoberyl/ alexandrite from India (Orissa), Brazil, Madagascar and Sri Lanka, and also phenomenal synthetic alexandrite from Kyocera in Japan. Sixteen oriented thin sections were studied by a combination of optical microscopy, micro-Raman spectroscopy, and electron microprobe techniques employing backscattered electron (BSE) imaging, qualitative point analysis and Ti compositional mapping. Rutile was identified as needle-like inclusions and V-shaped platelets in planes perpendicular to the a-axis, elongated parallel to the c-axis, and parallel to symmetry-equivalent <011> directions. Additional structures consisting of rutile needles and/or channels in various samples were oriented parallel to the a-axis. Also observed were single or multiple-intergrown rutile platelets elongated parallel to the a-axis, and rutile platelets showing rectangular, L-shaped or zigzag crosssections parallel to <012> directions. In a four-rayed star chrysoberyl, elongated ilmenite particles were oriented along the c-axis. Various optical effects such as a whitish appearance, asterism or chatoyancy are caused by, and depend upon, the presence, size and concentration of the combined different types of needlelike or platy inclusions. [ABSTRACT FROM AUTHOR]

The article discusses the 2015 Gem-A Conference and 18th International Federation for European Education in Gemmology (FEEG) meeting held in London, England on November 21-22, 2016, with seminars and workshops on jewels.

The article announces the qualified students taking the Gem-A examinations for the Gemmology Diploma including those with distinction and merit awards.

Mineralogical and gemmological data of two intensely coloured chrysoberyls from Brazil are presented. Both samples are twinned, and they appear violet-purple or purple in daylight, and reddish purple or red-purple in incandescent light. They have good transparency, but appear very dark in reflected light due to their enriched chromium contents. In one sample, an average of 1.54 wt.% Cr2O3 was measured, together with 0.60 wt.% Fe2O3. The high Cr content is responsible for a reduced transmission in the blue-green range of the visible spectrum, which causes a shift in the daylight coloration from blue-green for typical Cr-bearing chrysoberyl (alexandrite) to violet-purple or purple for such samples with distinctly higher Cr values. [ABSTRACT FROM AUTHOR]

Bill also authored several books, including Guide to Affordable Gemology, Naming Gem Garnets and Determinative Gemology. 538 THE JOURNAL OF GEMMOLOGY, 37(5), 2021 GEM-A NOTICES OBITUARIES Dr Walter William (Bill) Hanneman 1934-2020 The name Bill Hanneman has become something of a household word in the field of gemmology, but not from any conventional approach to the field. More filters were to follow, including those for ruby, aquamarine, tanzanite and synthetic emerald (the last one developed with this author and named the Hanneman/Hodgkinson Synthetic Emerald Filter). [Extracted from the article]

The article reports on the display of a prismatic gem-quality crystal obtained in Tanzania by gem dealer Werner Radl of Mawingu Gems during the 2015 Tucson Gem shows.

The article discusses the discovery of low molecular weight mercaptans in tanzanites from Merelani, Tanzani, which caused the rotten egg-like smell of the mineral. Topics discussed include the definition of the term, stinkstein or stinkstone, to describe minerals' odors, as well as first use in 1546 in Agricola and findings from the research to identify the source of the distinctive smell of tanzanites from Merelani.

The article offers information on the qualities and attributes of the spurrite discovered at the Tres Hermanas Mountains in Luna County, New Mexico.

The article lists several books on gemstones including "Geographic Origin Determination of Colored Gemstones," by Zhang Beili, Dietmar Schwarz and Taijin Lu, "Charles Edenshaw," by Dana Augaitis, Jim Hart and Robin K. Wright, and "Vintage Jewellery Sourcebook," by Caroline Cox.

The article focuses on the analysis of a claimed 'natural saltwater pearl' by the Laboratorie Francais de Gemmologie (LFG), which was described as a round light grey pearl and appears to come from the Pinctada maxima species. Topics discussed include the tools used to investigate the pearl's natural or cultured origin, the round homogeneous structure as a central bead found while observing radiographs and the X-radiography technology designed to analyze pearls.

The article discusses the China Gems & Jewelry Academic Exchange Conference that took place on November 30, 2015 in Beijing.

Information about the American Gem Trade Association (AGTA) GemFair Tucson Seminars held in Tucson, Arizona from February 3 to 6, 2016 is presented where attendees listened to the discussion about marketing, jewelry identification and gem mining.