TY - JOUR
T1 - Shkatulkalite, a rare mineral from the Lovozero Massif, Kola Peninsula
T2 - A re-investigation
AU - Zolotarev, Andrey A.
AU - Selivanova, Ekaterina A.
AU - Krivovichev, Sergey V.
AU - Savchenko, Yevgeny E.
AU - Panikorovskii, Taras L.
AU - Lyalina, Lyudmila M.
AU - Pautov, Leonid A.
AU - Yakovenchuk, Victor N.
PY - 2018/7/18
Y1 - 2018/7/18
N2 - The crystal structure of shkatulkalite has been solved from the crystal from the Lovozero alkaline massif, Kola Peninsula, Russia. The mineral is monoclinic, P2/m, a = 5.4638(19), b = 7.161(3), c = 15.573(6) angstrom, beta= 95.750(9)degrees , V = 606.3(4) angstrom(3), R-1 = 0.080 for 1551 unique observed reflections. The crystal structure is based upon the HOH blocks consisting of one octahedral (O) sheet sandwiched between two heteropolyhedral (H) sheets. The blocks are parallel to the (001) plane and are separated from each other by the interlayer space occupied by Na1 atoms and H2O groups. The Na2, Na3, and Ti sites are located within the O sheet. The general formula of shkatulkalite can be written as Na-5(Nb1-xTix)(2)(Ti(1-y)Mn(2+)y)[Si2O7](2)O-2(OH)(2).nH(2)O, where x + y = 0.5 and x approximate to y approximate to 0.25 for the sample studied. Shkatulkalite belongs to the seidozerite supergroup and is a member of the lamprophyllite group. The species most closely related to shkatulkalite are vuonnemite and epistolite. The close structural relations and the reported observations of pseudomorphs of shkatulkalite after vuonnemite suggest that, at least in some environments, shkatulkalite may form as a transformation mineral species.
AB - The crystal structure of shkatulkalite has been solved from the crystal from the Lovozero alkaline massif, Kola Peninsula, Russia. The mineral is monoclinic, P2/m, a = 5.4638(19), b = 7.161(3), c = 15.573(6) angstrom, beta= 95.750(9)degrees , V = 606.3(4) angstrom(3), R-1 = 0.080 for 1551 unique observed reflections. The crystal structure is based upon the HOH blocks consisting of one octahedral (O) sheet sandwiched between two heteropolyhedral (H) sheets. The blocks are parallel to the (001) plane and are separated from each other by the interlayer space occupied by Na1 atoms and H2O groups. The Na2, Na3, and Ti sites are located within the O sheet. The general formula of shkatulkalite can be written as Na-5(Nb1-xTix)(2)(Ti(1-y)Mn(2+)y)[Si2O7](2)O-2(OH)(2).nH(2)O, where x + y = 0.5 and x approximate to y approximate to 0.25 for the sample studied. Shkatulkalite belongs to the seidozerite supergroup and is a member of the lamprophyllite group. The species most closely related to shkatulkalite are vuonnemite and epistolite. The close structural relations and the reported observations of pseudomorphs of shkatulkalite after vuonnemite suggest that, at least in some environments, shkatulkalite may form as a transformation mineral species.
KW - CRYSTAL-CHEMISTRY
KW - EPISTOLITE
KW - EXCHANGE
KW - Kola Peninsula
KW - Lovozero alkaline massif
KW - RUSSIA
KW - STRUCTURE TOPOLOGY
KW - SUPERGROUP
KW - TITANIUM DISILICATE MINERALS
KW - TITANOSILICATES
KW - TS-BLOCK MINERALS
KW - crystal structure
KW - niobium
KW - shkatulkalite
KW - titanium
KW - titanosilicate
KW - transformation mineral species
KW - vuonnemite
UR - http://www.scopus.com/inward/record.url?scp=85050655345&partnerID=8YFLogxK
U2 - 10.3390/min8070303
DO - 10.3390/min8070303
M3 - Article
AN - SCOPUS:85050655345
VL - 8
SP - 303
JO - Minerals
JF - Minerals
SN - 2075-163X
IS - 7
M1 - 303
ER -