IMA 2012-042 = voudourisite; IMA 2012-043 = lazaridisite

database, nuove specie, discrediti,
ridefinizioni, classificazioni, ecc.
Rispondi
Avatar utente
Marco E. Ciriotti
Messaggi: 24918
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
Contatta:

IMA 2012-042 = voudourisite; IMA 2012-043 = lazaridisite

Messaggio da Marco E. Ciriotti » sab 10 nov, 2018 11:02

Prossima pubblicazione.

Referenza:
▪ Rieck, B., Lengauer, C.L., Giester, G. (2018): Voudourisite, Cd(SO4)·H2O, and lazaridisite, Cd3(SO4)3·8H2O, two new minerals from the Lavrion Mining District, Greece. Mineralogical Magazine, 82, (in press).

Abstract:
Voudourisite, Cd(SO4)·H2O, and lazaridisite, Cd3(SO4)3·8H2O, are two new minerals from the Esperanza Mine, Kaminiza Area, Lavrion Mining District, Greece. The small ancient mine also is the type-locality of niedermayrite and katerinopoulosite. Further associated minerals are sphalerite, galena, edwardsite, chalcanthite, gypsum and greenockite. Both secondary minerals form tiny clusters or crusts and are among the latest to form in this paragenetic sequence. They are colorless or white, transparent to translucent, with white streak and vitreous luster. No fluorescence is observed. The minerals exhibit conchoidal fracture, no cleavage or preferred parting. The Mohs hardness is ~3 and both have brittle tenacity. Voudourisite is biaxial (–) with refractive indices at 589(1) nm α = 1.580(2), β = 1.624(2), γ = 1.640(2), 2V (meas.) = 70(5)°, 2V (calc.) = 61°, β ~ || [010] while lazaridisite is biaxial neutral with refractive indices at 589(1) α = 1.552(2), β = 1.561(2), γ = 1.570(2), 2V (meas.) = 90(5)° and 2V (calc.) = 90°. The chemical compositions of voudourisite and lazaridisite are close to ideal with only minor amounts of copper detectable. The atomic arrangement in voudourisite (space group P21/c with a = 7.633(2), b = 7.458(2), c = 8.151(2) Å, β = 122.35(1)°, V = 392.0(2) Å3) is related to that of kieserite while lazaridisite (space group C2/c with a = 14.813(3), b = 11.902(2), c = 9.466(2) Å, β = 97.38(1)°, V = 1655.2(6) Å3) is a distinct structure-type. Calculated densities are 3.838 and 3.088 g/cm3, respectively.
The strongest lines in the X-ray powder pattern [d in Å, (I), (hkl)] are: 4.890, (66), (1 1 0); 3.741, (25), (0 2 0); 3.578, (100), (1 1 -2); 3.230, (43), (2 0 0); 2.525, (33), (0 2 2); 2.395, (29), (1 1 2) for voudourisite and 6.860, (100), (2 0 0); 6.317, (72), (1 1 1); 5.965, (84), (0 20); 4.512, (58), (3 1 0); 3.727, (78), (2 0 2); 3.608, (82), (1 3 -1); 3.109, (83), (4 0 -2); 3.020, (50), (3 3 -1) for lazaridisite, respectively.

NdR: lazaridhisite should be the correct name because named after Stathis Lazaridhis (1953-2010), a mineral collector from Lavrion, who contributed significantly to nowadays understanding of the paragenetic sequences within the Lavrion deposits.
Three potential new species, at present as approved or as proposals or in study, are mentioned in the paper.
Marco E. Ciriotti

«Things are interesting only in so far as they relate themselves to other things»

Rispondi

Chi c’è in linea

Visitano il forum: Nessuno e 3 ospiti