Detailed Information on Publication Record
2018
The crystal chemistry of the sakhaite-harkerite solid solution
EVANS, RJ, LA GROAT, Jan CEMPÍREK, Radek ŠKODA, ES GREW et. al.Basic information
Original name
The crystal chemistry of the sakhaite-harkerite solid solution
Authors
EVANS, RJ (124 Canada), LA GROAT (124 Canada), Jan CEMPÍREK (203 Czech Republic, guarantor, belonging to the institution), Radek ŠKODA (203 Czech Republic, belonging to the institution), ES GREW (840 United States of America) and C. BERNARD (124 Canada)
Edition
American Mineralogist, Chantilly, Mineralogical Society of America, 2018, 0003-004X
Other information
Language
English
Type of outcome
Článek v odborném periodiku
Field of Study
10504 Mineralogy
Country of publisher
United States of America
Confidentiality degree
není předmětem státního či obchodního tajemství
References:
Impact factor
Impact factor: 2.631
RIV identification code
RIV/00216224:14310/18:00101776
Organization unit
Faculty of Science
UT WoS
000448917700005
Keywords in English
sakhaite; harkerite; solid solution; crystal structure; lithium; beryllium; boron
Tags
International impact, Reviewed
Změněno: 23/4/2024 14:30, Mgr. Michal Petr
Abstract
V originále
Sakhaite, ca. Ca48Mg16(BO3)(32)(CO3)(16)(HCl,H2O)(2), is a rare rock-forming borate-carbonate mineral typically occurring in high-temperature, low-pressure calcareous skarns. It forms a complete solid solution with harkerite, ca. Ca48Mg16[AlSi4(O,OH)(16)](4)(BO3)(16)(CO3)(16)(HCl,H2O)(2). The solid solution can be described with the general formula Ca-48(Mg, Fe, Mn)(16)(CO3)(16)[AlaSi5-a(O,OH)(16)](y)(BO3)(32-4y)(HCl,H2O)(n) where y(max) = 8 and n(max) = 16 - y. In this study, we examine samples of sakhaite and harkerite from four localities worldwide: Titovskoye deposit, Sakha Republic, Russia (type locality for sakhaite); Solongo B deposit, Buryatia Republic, Russia; Camas Malag, Skye, Scotland (type locality for harkerite); as well as a sakhaite-like mineral from the Kombat Mine, Tsumeb. The Si:B ratios of the samples ranged from that of end-member sakhaite (containing B only) to that of end-member harkerite (Si:B = 1:1), with several intermediate compositions. All samples were deficient in B relative to the ideal composition, implying significant substitution for borate groups. The Si:Al ratio of silicate-containing samples ranged from the ideal 4:1 to 4:1.5, implying substitution of Al at the Si site. The cubic unit-cell parameter was found to increase linearly with increasing Si content, except for the sakhaite-like mineral from Tsumeb. This mineral was found to have significant substitution of Pb for Ca (0.4-0.5 apfu) and was poor in Cl, which in most sakhaite and harkerite samples occupies the interstitial site surrounded by four borate groups. This interstitial site in the Tsumeb samples appears to be, instead, mainly occupied by H2O, which may qualify the mineral as a distinct species.
Links
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