L’œil de Sainte-Lucie

Thomas Cagniard (1), Jean-Pierre Gauthier (2) & Jacques Fereire (2) DOI : https://doi.org/10.63000/wq5XXR9f68 Abstract Highlighted by popular belief, the eye of Saint-Lucia is a biomineral, which is of undoubted gemological interest by its nature and through its use. As gastropod operculum of the species Bolma rugosa, its name is not protected and may have been […]

Revue GEMMES, troisième numéro, printemps 2024

C’est avec beaucoup de fierté et de joie que nous vous annonçons la sortie du troisième numéro de la revue GEMMES. Au sommaire de ce numéro, vous retrouverez les contributions de Stéphane Renard, Thomas Cagniard, Féodor Blumentritt, Aurélien Delaunay, Franck Notari, Ingrid Lerouyer, Boris Chauviré, Clara Allirol-Mouton, Marianna Corre, Emmanuel Fritsch, Chloé Picard, Lauriane Pinsault, […]

La coquille flammée du casque rouge, Cypraecassis rufa

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 […]

Une remarquable tourmaline elbaïte non cuprifère

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 […]

Kreuter (1842-1987), fabricant méconnu

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 […]

Les verres naturels

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 […]

Revue sur les minéraux de qualité gemme du Canada.

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 […]

Méthodes de calcul des formules structurales des gemmes

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 […]