Jean-Pierre Gauthier (1), Jacques Fereire (1) & Thanh Nhan Bui (2) DOI : https://doi.org/10.63000/2v7Zd89UZz Abstract The flame structure of the red helmet shell, Cypraecassis rufa (Linnaeus, 1758) Among molluscs with so-called “porcelaneous” shells, consisting of non-nacreous aragonite, we chose a gastropod, Cypraecassis rufa, to show an example of flame structure on cabochon-cut samples. The crossed […]
Franck Notari (1) (2), Féodor Blumentritt (2), Yolchanok Srinaka (1), Natthawut Saenkuntha (1) DOI : https://doi.org/10.63000/546HduNg2 Abstract The popularity of Paraíba-type tourmalines is mainly due to their remarkable colour, often described as « neon » blue. Many tourmalines with this colour are traded under the label Paraíba, but sometimes mistakenly. Today, gemmological laboratories devote particular attention to […]
Aurore SAYS (1) DOI : https://doi.org/10.63000/i33EM7H9rc Abstract Jade is considered one of the most precious stones in the world. In Chinese, 玉 Yù is a word used to describe a very beautiful gem, it could also be simply translated by « precious ». It is the general name for “jade” and its different mineralogical varieties, such as […]
Marie Chabrol (1) & Charline Coupeau (2) DOI : https://doi.org/10.63000/G63qeC95cN Abstract The city of Hanau in Germany was one of the most important jewelry production centers of Europe between the end of the 19th century and the beginning of the 20th. It’s in this city that the Kreuter workshop was based, which ensured most of […]
Ingrid Lerouyer (1) DOI : https://doi.org/10.63000/h8Y99yeDB3 Abstract This article presents the main varieties of natural glasses and classifies them into three categories, each linked to their mode of formation. In the wild, glass can be found through volcanic, meteoritic impact or lightning-related events. At the end of this article, a table lists the characteristics and […]
Daphné Giacomazzi (1), Marianne Dragon (1), Marie-Hélène Corbin(1) DOI : https://doi.org/10.63000/46Z4SCg3qf Abstract Canada is a country rich in its diversity of minerals, some of which have gem varieties. Yet only three gemstones are of both local and international economic importance: the diamond, the nephrite jade and the ammolite. Other gems, such as hessonite garnet, are […]
Marie-Laure Cassius-Duranton (1) DOI : https://doi.org/10.63000/z32LVB3f2e Abstract Among pearl origin myths, one of the most widespread in Western European culture was handed down to us by Pliny the Elder: a shell fertilized by dew would give birth to the pearl. This myth became a topos in the lapidaries and bestiaries of the Middle Ages, as […]
Marine Bouvier (1) DOI : https://doi.org/10.63000/9J9TCb9k2h Abstract This article aims to explain the content of the experimental dissertation prepared by Marine Bouvier (2023) for her university diploma in gemology (DUG, Nantes entitled “Calculation methods of structural formulas for gemstones”. The utilities and uses of the structural formulas are explained, along with the percentage of pure […]
Chloé Picard (1) DOI : https://doi.org/10.63000/5Fz5wu8Y ABSTRACT The adjective sustainable (“durable” in French) is, according to the French dictionary Petit Robert, “likely to last a long time”. Still according to this noble book, a company is defined as “an organization for the production of goods or services of a commercial nature”. To last, a company […]
Emmanuel Fritsch1, Nicolas Hébert2, Feodor Blumentritt1,3, Cassandre Moinard1 ABSTRACT A parcel of 13 kg of hackmanite from the Mogok area, Myanmar triggered some surprising observations that contribute to the knowledge of hackmanite, the photochromic variety of sodalite. Firstly, we point out that nearly 350 samples reach exactly the same color saturation under UV-rich natural sunlight […]
