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...
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....
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...
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,...
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...
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...
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...
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...
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...