TY - JOUR

T1 - Berthierine-2H1 from Lovozero Alkaline Massif, Kola Peninsula, Russia: First Structure Model for Berthierine and Complexity-Stability Relations

AU - Кривовичев, Сергей Владимирович

AU - Яковенчук, Виктор Нестерович

AU - Пахомовский, Яков, А.

AU - Гойчук , Ольга Фёдоровна

AU - Кривовичев, Владимир Герасимович

N1 - Krivovichev, S.V.; Yakovenchuk, V.N.; Goychuk, O.F.; Pakhomovskii, Y.A.; Krivovichev, V.G. Berthierine-2H1 from Lovozero Alkaline Massif, Kola Peninsula, Russia: First Structure Model for Berthierine and Complexity-Stability Relations. Minerals 2025, 15(1), No13. https://doi.org/10.3390/min15010013

PY - 2025/1/1

Y1 - 2025/1/1

N2 - Berthierine was found in a natrolite vein intersecting volcanogenic-sedimentary rocks on the slope of Mt. Quamdespakh in the upper reaches of the Suolwai River, Lovozero alkaline massif, Kola peninsula, Russian Arctic. The mineral occurs as well-formed translucent pyramidal crystals up to 250 μm in size. The chemical composition determined by electron microprobe analysis corresponds to the empirical formula VI(Fe2+1.99Al0.94Mg0.03Mn0.04)Σ3.00[IV(Si1.15Al0.85)Σ2.00O5] [(OH)3.92O0.08]Σ4.00; the idealized formula is VI(Fe2+2Al)[IV(SiAl)O5](OH)4. The crystal-structure determination (the first detailed crystal-structure characterization of berthierine) shows that the Lovozero mineral is hexagonal, P63cm (a = 5.3903(4), c = 14.0146(10) Å, V = 352.64(6) Å3, R1 = 0.053 for 338 unique observed reflections), and corresponds to the 2H1 polytype of serpentine-group minerals with 1:1 tetrahedral-octahedral layers. The unit cell contains two M3[T2O5](OH)4 layers (M = Fe2+,Al; T = Si,Al) stacked along the c axis. The calculations of information-based structural and topological complexity parameters indicate that berthierine is structurally and topologically simpler than its chlorite-group polymorph chamosite. Since berthierine usually crystallizes metastably in the stability field of chamosite, the complexity analysis is agreement with the Goldsmith rule that states that, in Ostwald sequences of crystallization, metastable phases are simpler and more disordered than their stable counterparts. This observation can be applied to a general case of the metastable formation of serpentine-group minerals prior to the crystallization of chlorites.

AB - Berthierine was found in a natrolite vein intersecting volcanogenic-sedimentary rocks on the slope of Mt. Quamdespakh in the upper reaches of the Suolwai River, Lovozero alkaline massif, Kola peninsula, Russian Arctic. The mineral occurs as well-formed translucent pyramidal crystals up to 250 μm in size. The chemical composition determined by electron microprobe analysis corresponds to the empirical formula VI(Fe2+1.99Al0.94Mg0.03Mn0.04)Σ3.00[IV(Si1.15Al0.85)Σ2.00O5] [(OH)3.92O0.08]Σ4.00; the idealized formula is VI(Fe2+2Al)[IV(SiAl)O5](OH)4. The crystal-structure determination (the first detailed crystal-structure characterization of berthierine) shows that the Lovozero mineral is hexagonal, P63cm (a = 5.3903(4), c = 14.0146(10) Å, V = 352.64(6) Å3, R1 = 0.053 for 338 unique observed reflections), and corresponds to the 2H1 polytype of serpentine-group minerals with 1:1 tetrahedral-octahedral layers. The unit cell contains two M3[T2O5](OH)4 layers (M = Fe2+,Al; T = Si,Al) stacked along the c axis. The calculations of information-based structural and topological complexity parameters indicate that berthierine is structurally and topologically simpler than its chlorite-group polymorph chamosite. Since berthierine usually crystallizes metastably in the stability field of chamosite, the complexity analysis is agreement with the Goldsmith rule that states that, in Ostwald sequences of crystallization, metastable phases are simpler and more disordered than their stable counterparts. This observation can be applied to a general case of the metastable formation of serpentine-group minerals prior to the crystallization of chlorites.

KW - Arctic

KW - Goldsmith principle

KW - Kola peninsula

KW - berthierine

KW - chamosite

KW - crystal structure

KW - metastability

KW - structural complexity

UR - https://www.mendeley.com/catalogue/fa73e039-7f9a-3575-9a35-be7afa8461dd/

U2 - 10.3390/min15010013

DO - 10.3390/min15010013

M3 - Article

VL - 15

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 1

M1 - 13

ER -