Oxygen: chemical element with the symbol O, atomic number 8, and an atomic mass of approximately 16 u. Molecular Oxygen (O₂), composed of two Oxygen atoms bonded together, makes up about 21% of the Earth’s atmosphere.
Oxygen: chemical element with the symbol O, atomic number 8, and an atomic mass of approximately 16 u. Molecular Oxygen (O₂), composed of two Oxygen atoms bonded together, makes up about 21% of the Earth’s atmosphere.
IGR (Rivista Italiana di Gemmologia/Italian Gemological Review) è la rivista gemmologica internazionale italiana, nata nel 2016 da Gem-Tech con l’obiettivo di sviluppare in Italia un network informativo per Gemmologi e per professionisti quotidianamente impegnati nel settore delle pietre preziose.
IGR – Rivista Italiana di Gemmologia, the Italian Gemological Review, is the leading International Gemological Magazine in Italy masterminded by Gem-Tech Gemological Institute, a broad information framework for Gemologists as well as professionals involved daily in the gemstone business.
Testata registrata al Tribunale di Napoli, reg. n. 15 del 18/05/2017.
Edita da: Gem Tech SRL – 80122 Napoli (Italy) - P. IVA IT09159321216
Contattaci / Contact us: info@rivistaitalianadigemmologia.com
© Copyright 2023 - IGR – Rivista Italiana di Gemmologia – Italian Gemological Review. Tutti i diritti riservati / All rights reserved
