Boscardinite, TlPb4(Sb7As2)Σ=9S18

Orlandi, P., Biagioni, C., Bonaccorsi, E., Moëlo, Y., Paar, W. (2011): Lead–antimony sulfosalts from Tuscany (Italy). XII. Boscardinite, TlPb4(Sb7As2)Σ=9S18, a new mineral from the Monte Arsiccio mine (Tuscany, Italy): occurrence and crystal structure. Canadian Mineralogist, 49, (in press).

Someone help me out with this formula, why isn't (Sb7As2) sufficient? Why do you need to do simple arithmetic in the formula?

It's a matter of taste. Sum symbols in such cases imply that the ratio of the elements in the parentheses are or may be variable to some extent.

Hi Matteo,

congratulation for your Mineral!!

Günter

>Sum symbols in such cases imply that the ratio of the elements in the parentheses are or may be variable to some extent.

Why invent a new format when (Sb,As) seems more logical? I'm sure there's a good reason - but I guess I'll have to wait until it's published to know!

Jolyon

Congratulazioni, grande Matteo Boscardin per questa specie a te dedicata...

I suppose that as Sb and As have a fixed number, the brackets are superfluous. But maybe they are used to show the total of As+Sb and so the relationship with other sulfosalts.



Edited 1 time(s). Last edit at 09/08/2011 04:09PM by Erik Vercammen.

Great Matteo, correct and deserved prize for the one who has given a lot to the study of the Italian mineralogy. Manuele.

All'amico Matteo congratulazioni!!!!!