I found the ways to estimate Li2O and H2O in amblygonite, Li2O = 1-(Na+K), OH=1-F, but I cannot convert wt% to apfu when I don't have total cation like suggestion in this website:
http://www4.nau.edu/microanalysis/Microprobe-SEM/Recalculation.html.
Any advice?
Actually the atom counts coordination of amblygonite calculated by one of the crystallographic methods of single crystal analysis. They calculated total amount of atoms stable to form T, M and A on per cell area. As you attached the table is theoretically calculated the stability of particular unit cell at T, M, and/or A based on conversion factor. It is doesn’t matter that you can selectively replace Li2O = Na/K, but try this calculation correction factor not exceeding the limited values as per given the table. In your calculation try to substitute Na equivalent weight instead of Li and divided by Oxygen factor (Li2 = 2Na and 2K). The normalization of cation moles and oxygen weights everything is given in your table. Make it use of these in your calculations. In your question how can I convert in weight % that’s for Summation all counts of equivalent weight (Σ eq. wt =T, M and A), These value divide by an individual wt. of T, M or A.
Good luck
Dear Colleague:
I remember a paper from the 60-ies, written by K. Perry:
An Application of Linear Algebra to Petrologic Problems: Part 1. Mineral Classification, 1967, Pergamon Press, Geochimica Et Cosmochimica Acta, 31 : 1043-1078, 3 figures and 15 tables.
I think this paper can help you.
With best regards
Szaniszlo Berczi
Dear Hien, You can use Minpet software or excel spreadsheets may available in web.
Qing Yang 1 ppm = 10^-4 wt%, 1 wt% = 10^4 ppm. In order to convert element contents to apfu you have to normalize them to the specific formula you know/assume.
Hien Dinh Gavril Săbău Thank you for your answers. In fact, I am analyzing the trace elements of sphalerite by LA-ICP-MS. I know that EPMA data(wt%) can be converted to apfu, so I want to convert LA data(ppm) to apfu. However, my colleague told me that the LA data(ppm) cannot be converted to apfu because the LA data is given in ppm and the EPMA data is given in wt%, but he did not explain clearly. As far as I know, I think LA data can be converted to apfu, as you said. I don't know if the LA-ICP-MS data(ppm) can be converted to wt% first, and then converted to apfu. Is there an essential difference between the LA data and the EPMA data given by the instruments?
I recommend you to read the appendix from
An Introduction to the Rock-Forming Minerals (Deer, Howie and Zussman)
The process is very nicely detailed. I do not recommend you to use any excel sheet or software because i think is very important for you to understand the procedure instead of copy paste some numbers.
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