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. Author manuscript; available in PMC: 2010 Dec 1.
Published in final edited form as: Appl Geochem. 2009 Dec 1;42(12):2234–2245. doi: 10.1016/j.apgeochem.2009.09.010

Figure 5.

Figure 5

X-ray diffraction patterns obtained after pertinent steps in the sequential extraction of T3.9. From top to bottom: (i) unextracted, (ii) unextracted minus water extracted, (iii) acid ammonium oxalate extracted (25°C); (iv) residual. Gypsum (G) dissolves during the water extraction, as shown by the difference diffractogram calculated from the patterns for unextracted minus water-extracted solids. Jarosite (J) peaks shown in the post-AAO 25°C pattern are removed during the subsequent extraction and are not present in the residual pattern, indicating jarosite dissolution during the AAO 80°C step. Following the acid extraction, only aluminosilicate phases remain. Minerals remaining after acid extraction include: quartz (Q), orthoclase (O), hedenbergite (H), johannsenite (N), Zn-talc (T), axinite (X), and andradite (A). Diffractograms for other extraction steps are not shown because there are no changes in the pattern.