Dear Mario, I only use PO to check if it applies. If yes, I make a new preparation to avoid PO. Also, graininess may look similar to PO, and this would surely bias QPA if PO refinement is allowed for.
So my advice is: grind, grind, grind. Best miguel On 27 Oct 2008 at 10:48, [EMAIL PROTECTED] wrote: > Dear all, > > I have this question, > > I have been refined one mixture (of well-know percentage composition) of > CaCO3, CaF2, SiO2 and Al2O3, with preferential orientation in CaCO3 (104) > and CaF2 (111) with good results. When I add to the mixture FeCO3 and I > refine with preferential orientation (104), it happens that when I don´t > apply the preferential orientation in all this phases, I have correct > values of percentage composition, but when I apply the preferential > orientation the refinement is good but with incorrect values of percentage > composition. This experiment has been taken in Bragg Brentano geometry. > How I should refine this mixture? > > Thanks a lot by your help. > > Mario Macías > Universidad Industrial de Santander > Colombia > > > -- Miguel Gregorkiewitz Dip Scienze della Terra, Università via Laterina 8, I-53100 Siena, Europe fon +39'0577'233810 fax 233938 email [EMAIL PROTECTED]
