J 2018

The crystal chemistry of the sakhaite-harkerite solid solution

EVANS, RJ, LA GROAT, Jan CEMPÍREK, Radek ŠKODA, ES GREW et. al.

Základní údaje

Originální název

The crystal chemistry of the sakhaite-harkerite solid solution

Autoři

EVANS, RJ (124 Kanada), LA GROAT (124 Kanada), Jan CEMPÍREK (203 Česká republika, garant, domácí), Radek ŠKODA (203 Česká republika, domácí), ES GREW (840 Spojené státy) a C. BERNARD (124 Kanada)

Vydání

American Mineralogist, Chantilly, Mineralogical Society of America, 2018, 0003-004X

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Spojené státy

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 2.631

Kód RIV

RIV/00216224:14310/18:00101776

Organizační jednotka

Přírodovědecká fakulta

DOI

UT WoS

000448917700005

Klíčová slova anglicky

sakhaite; harkerite; solid solution; crystal structure; lithium; beryllium; boron

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 23. 4. 2024 14:30, Mgr. Michal Petr

Anotace

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.

Návaznosti

GA17-17276S, projekt VaV
Název: Turmalín - indikátor geologických procesů
Investor: Grantová agentura ČR, Turmalín - indikátor geologických procesů