Fig. 2. (a) X-ray diffraction (XRD) patterns of quartz and the mixed sample after 14 d of reaction (Q, quartz; B, biotite; C, cancrinite; S, sodalite); (b) XRD patterns of reacted quartz as a function of time. Arrows indicate typical peaks of cancrinite. Single mineral nitrate cancrinite was separately synthesized according to Buhl et al. (2000).