There are also plenty cases cited in the literature that suggest at
least some Ti4+ is present at tetrahedrally coordinated sites in Ti-
bearing garnets from alkaline igneous rocks.
e.g., <http://www.cosis.net/abstracts/EAE03/05605/EAE03-J-05605.pdf>
John
On 27 Jan2008, at 08:11, r h wrote:
> Dear list members,
>
>
> I am recently working on some high Ti-bearing garnets (mainly
> melanite) in alkaline rocks. I have a problem in allocating cations
> to appropriate crystallographical sites. I have microprobe analyses
> of major oxides in the garnet, but there is no information on Ti and
> Fe valance state in these minerals. Are you aware of a practical
> method (or software) for calculating formula of such unusual
> garnets? Any idea how R-mode for factor matrix can be calculated
> (Table 3 of paper by Dingwell and Brearley, Cont. Min.Pet.,1985, 90:
> 29-35).
>
> Sincerely
>
>
> R. Hajialioghli
>
> Support the World Aids Awareness campaign this month with Yahoo! for
> Good
|