Siderite
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R050262
      Graf D L
      American Mineralogist 46 (1961) 1283-1316
      Crystallographic tables for the rhombohedral carbonates

      CELL PARAMETERS:   4.688700   4.688700   15.37300   90.00000   90.00000   120.0000
      SPACE GROUP: R-3c
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                24.89         36.39        3.5799    0   1   2
                32.20        100.00        2.7811    1   0   4
                38.50         21.30        2.3387    1   1   0
                42.53         16.17        2.1259    1   1   3
                46.38         19.36        1.9579    2   0   2
                51.02         10.77        1.7899    0   2   4
                52.94         19.12        1.7295    0   1   8
                53.13         28.25        1.7236    1   1   6
                60.79          1.73        1.5234    2   1   1
                61.78         12.44        1.5013    1   2   2
                65.16          2.50        1.4313    1   0  10
                65.67         10.04        1.4214    2   1   4
                67.32          4.14        1.3906    2   0   8
                68.18          2.14        1.3751    1   1   9
                68.51          1.01        1.3692    1   2   5
                69.61          9.74        1.3503    3   0   0
                74.37          3.39        1.2750    0   0  12
                78.28          2.88        1.2208    0   2  10
                80.29          5.09        1.1952    1   2   8
                87.00          3.17        1.1195    1   1  12
                87.00          3.17        1.1195    1   1  12
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.