J 2022

Princivalleite, Na(Mn2Al)Al6(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup from Veddasca Valley, Varese, Italy

BOSI, Ferdinando; Federico PEZZOTTA; Henrik SKOGBY; Alessandra ALTIERI; Ulf HALENIUS et. al.

Základní údaje

Originální název

Princivalleite, Na(Mn2Al)Al6(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup from Veddasca Valley, Varese, Italy

Autoři

BOSI, Ferdinando (garant); Federico PEZZOTTA; Henrik SKOGBY; Alessandra ALTIERI; Ulf HALENIUS; Gioacchino TEMPESTA a Jan CEMPÍREK (203 Česká republika, domácí)

Vydání

Mineralogical Magazine, Cambridge University Press, 2022, 0026-461X

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 2.700

Kód RIV

RIV/00216224:14310/22:00119720

Organizační jednotka

Přírodovědecká fakulta

DOI

UT WoS

000752937900001

EID Scopus

2-s2.0-85123836111

Klíčová slova anglicky

princivalleite; new mineral species; crystal-structure refinement; electron microprobe; Mossbauer spectroscopy; infrared spectroscopy; optical absorption spectroscopy; micro-laser induced breakdown spectroscopy

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 29. 3. 2022 12:37, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

Princivalleite, Na(Mn2Al)Al6(Si6O18)(BO3)3(OH)3O, is a new mineral (IMA2020-056) of the tourmaline supergroup. It occurs in the Veddasca Valley, Luino area, Varese, Lombardy, Italy (46°03’30.74’’N, 8°48’24.47’’E) at the centre of a narrow (2–3 cm wide) vertical pegmatitic vein, a few metres long, crosscutting a lens of flaser gneiss. Crystals are subhedral (up to 10 mm in size), azure with a vitreous lustre, conchoidal fracture and white streak. Princivalleite has a Mohs hardness of ~7, a calculated density of 3.168 g/cm3 and is uniaxial (–). Princivalleite has trigonal symmetry, space group R3m, a = 15.9155(2) Å, c = 7.11660(10) Å, V = 1561.15(4) Å3 and Z = 3. The crystal structure was refined to R1 = 1.36% using 1758 unique reflections collected with MoKα X-ray intensity data. Crystal-chemical analysis resulted in the empirical crystal-chemical formula X(Na0.54Ca0.11□0.35)Σ1.00Y(Al1.82Mn2+0.84Fe2+0.19Zn0.07Li0.08)Σ3.00Z(Al5.85Fe2+0.13Mg0.02)Σ6.00[T(Si5.60Al0.40)Σ6.00O18](BO3)3O(3)[(OH)2.71O0.29]Σ3.00O(1)[O0.66F0.22(OH)0.12]Σ1.00 which recast in its ordered form for classification purposes is: X(Na0.54Ca0.11□0.35)Σ1.00 Y(Al1.67Mn2+0.84Fe2+0.32Zn0.07Mg0.02Li0.08)Σ3.00 ZAl6.00[T(Si5.60Al0.40)Σ6.00O18](BO3)3V[(OH)2.71O0.29]Σ3.00W[O0.66F0.22(OH)0.12]Σ1.00. Princivalleite is an oxy-species belonging to the alkali group of the tourmaline supergroup. The closest end-member compositions of valid tourmaline species are those of oxy-schorl and darrellhenryite, to which princivalleite is related by the substitutions Mn2+ ↔ Fe2+ and Mn2+ ↔ 0.5Al3+ + 0.5Li+, respectively. Princivalleite from Veddasca Valley is a geochemical anomaly, originated in a B-rich and peraluminous anatectic pegmatitic melt formed in situ, poor in Fe and characterised by reducing conditions in the late-stage metamorphic fluids derived by the flaser gneiss. The Mn-enrichment in this new tourmaline is due to absence of other minerals competing for Mn such as garnet.

Návaznosti

GA19-05198S, projekt VaV
Název: Greisenizace a albitizace - geologické procesy s potenciálem koncentrovat některé kritické suroviny pro moderní technologie (Akronym: GREISEN)
Investor: Grantová agentura ČR, Greisenizace a albitizace - geologické procesy s potenciálem koncentrovat některé kritické suroviny pro moderní technologie