Table T2. Positions of diagnostic peaks used for the identification of minerals in X-ray diffractograms and for quantification of peak intensities.
 
Mineral Peak (2) Peak ()
Quartz 26.65 3.34
K-Feldspar 26.93-27.52 3.31-3.24
Plagioclase 27.77-28.13 3.21-3.17
Hornblende 10.30-10.70 8.59-8.27
Calcite 29.45 3.03
Dolomite 30.94 2.89
Pyrite 33.05 2.71
Siderite 32.07 2.79
Opal-CT 21.94-21.67 4.05-4.10
Clinoptilolite 9.83 8.99

Note: Opal A shows a very broad peak around 4 .