2022
Crystal-Chemical Observations and the Relation Between Sodium and H2O in Different Beryl Varieties
HENRY, Rhiana E.; Lee A. GROAT; R. James EVANS; Jan CEMPÍREK; Radek ŠKODA et. al.Základní údaje
Originální název
Crystal-Chemical Observations and the Relation Between Sodium and H2O in Different Beryl Varieties
Autoři
HENRY, Rhiana E. (garant); Lee A. GROAT; R. James EVANS; Jan CEMPÍREK (203 Česká republika, domácí) a Radek ŠKODA (203 Česká republika, domácí)
Vydání
Canadian Mineralogist, Mineralogical Association of Canada, 2022, 0008-4476
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10504 Mineralogy
Stát vydavatele
Kanada
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 0.900
Kód RIV
RIV/00216224:14310/22:00128030
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000861174800003
EID Scopus
2-s2.0-85138945043
Klíčová slova anglicky
beryl; crystallography; water; sodium; mineralogy; crystal chemistry; emerald; aquamarine
Štítky
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 17. 1. 2023 10:25, Mgr. Marie Novosadová Šípková, DiS.
Anotace
V originále
Beryl (Be3Al2Si6O18) is a well-known mineral, most famously in its vivid green form of emerald, but also as a range of other colors. Prominent varieties of beryl aside from emerald include aquamarine, red beryl, heliodor, goshenite, and morganite. There has not been a significant amount of research dedicated to comparing the crystal-chemical differences among the varieties of beryl except in determining chromophoric cations. While the H2O content within structural channels of emerald has been explored, and the H2O content of individual beryl specimens has been studied, there has not yet been a study comparing the H2O content systematically across beryl varieties. In this study we consider single-crystal X-ray diffraction data and electron probe microanalyses of 80 beryl specimens of six primary varieties, to compare and contrast their crystal chemistry. Beryl cation substitutions are dominantly coupled substitutions that require Na to enter a structural channel site. The results indicate that with increasing Na content beryl varieties diverge into two groups, characterized by substitutions at octahedral or tetrahedral sites, and that the dominant overall cation substitutions in each beryl variety tend to be different in more than just their chromophores. We find that the relation between Na and H2O content in beryl is consistent for beryl with significant Na content, but not among beryl with low Na content. Natural red beryl is found to be anhydrous, and heliodor has Na content too low to reliably determine H2O content from measured Na. We determined equations and recommendations to relate the Na and H2O content in emerald, aquamarine, goshenite, and morganite from a crystallographic perspective that is applicable to beryl chemistry measured by other means. This research will help guide future beryl studies in classifying beryl variety by chemistry and structure and allow the calculation of H2O content in a range of beryl varieties from easily measured Na content instead of requiring the use of expensive or destructive methods.