Siderite
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R050349
      Graf D L
      American Mineralogist 46 (1961) 1283-1316
      Crystallographic tables for the rhombohedral carbonates

      CELL PARAMETERS:   4.686838   4.686838   15.34022   90.00000   90.00000   120.0000
      SPACE GROUP: R-3c
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                24.79         36.39        3.5876    0   1   2
                32.08        100.00        2.7876    1   0   4
                38.38         21.30        2.3434    1   1   0
                42.39         16.17        2.1304    1   1   3
                46.23         19.36        1.9619    2   0   2
                50.86         10.77        1.7938    0   2   4
                52.75         19.12        1.7338    0   1   8
                52.96         28.25        1.7275    1   1   6
                60.61          1.73        1.5265    2   1   1
                61.60         12.44        1.5043    1   2   2
                64.93          2.50        1.4350    1   0  10
                65.47         10.04        1.4244    2   1   4
                67.10          4.14        1.3938    2   0   8
                67.94          2.14        1.3784    1   1   9
                68.30          1.01        1.3721    1   2   5
                69.40          9.74        1.3530    3   0   0
                74.10          3.39        1.2784    0   0  12
                78.01          2.88        1.2238    0   2  10
                80.03          5.09        1.1979    1   2   8
                86.69          3.17        1.1222    1   1  12
                86.69          3.17        1.1222    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.