Copiapite, GRR 167, Alcaparrosa, Chile,  (poor surface polish)
0.180 mm, beta,  Room Temp, slits 1.0 mm.  
2200.3, .052
2198.8, .051
2193.6, .051
2192.1, .052
2186.9, .053
2180.1, .055
2171., .055
2164.9, .058
2158.1, .062
2149., .066
2140.6, .069
2133.7, .074
2126.1, .08
2119.2, .085
2110.8, .091
2103.1, .096
2095.5, .1
2088.6, .107
2084.8, .111
2080.9, .114
2076.3, .118
2072.5, .121
2068.7, .123
2065.6, .126
2023.7, .198
2019., .206
2014.5, .208
2010.7, .208
2008.4, .206
2006.2, .204
2004., .201
2001., .195
1996.6, .189
1991.5, .18
1987.8, .174
1984.2, .167
1979.1, .16
1972.4, .15
1968.1, .142
1964.4, .136
1961.5, .132
1957.1, .126
1951.8, .124
1949.6, .125
1945.8, .127
1943.5, .13
1941.2, .134
1938.9, .138
1936.6, .14
1934.4, .14
1933.7, .138
1931.5, .13
1930.1, .126
1928.7, .12
1928., .116
1926.5, .111
1925.9, .105
1923.7, .099
1922.4, .09
1921.7, .082
1920.3, .076
1919.6, .072
1918.9, .069
1919.7, .067
1914.7, .052
1914., .047
1913.3, .043
1912.6, .038
1912., .032
1909.8, .025
1908.4, .019
1907., .013
1904.9, .006
1902.7, .
1900.6, -.007
1898.4, -.014
1896.3, -.019
1894.8, -.025
1891.9, -.031
1886.8, -.038
1877.9, -.046
1871.2, -.049
1858.5, -.051
1850.3, -.049
1839.7, -.046
1833., -.044
1825.4, -.042
1822.4, -.04
1814.9, -.039
1808.2, -.038
1799.9, -.034
1797.6, -.034
1793.1, -.033
1786.4, -.033
1779.6, -.034
1771.4, -.035
1764.7, -.035
1757.2, -.034
1748.9, -.034
1740.7, -.034
1733.2, -.035
1721.3, -.036
1707.1, -.039
1695.9, -.041
1684.7, -.044
1674.2, -.046
1666., -.05
1658.6, -.053
1651.9, -.056
1643.7, -.06
1632.6, -.064
1627.3, -.067
1622.9, -.068
1614.7, -.07
1605.7, -.072
1595.2, -.074
1586.3, -.075
1578., -.075
1568.3, -.074
1560., -.074
1551.8, -.073
1544.3, -.072
1536.8, -.072
1529.3, -.073
1524.8, -.074
1520.3, -.074
1512.1, -.077
1507.7, -.078
1500.9, -.079
1491.3, -.08
1481.6, -.08
1475.6, -.079
1471.9, -.078
1466.7, -.076
1462.9, -.073
1460.6, -.07
1458.4, -.068
1456.1, -.065
1455.4, -.064
1453.1, -.064
1450.9, -.065
1450.2, -.067
1448.7, -.069
1447.3, -.072
1445.9, -.077
1445.2, -.08
1443.7, -.082
1441.6, -.088
1439.4, -.092
1435.8, -.097
1431.4, -.103
1429.2, -.108
1425.6, -.113
1420.5, -.118
1416.8, -.123
1414.6, -.126
1413.1, -.127
1411.7, -.129
1402.1, -.135
1393.2, -.138
1385.7, -.14
1380.5, -.141
1376.8, -.139
1373.1, -.138
1367.2, -.139
1359.8, -.139
1350.9, -.139
1336.8, -.139
1323.4, -.141
1311.6, -.142
1302.6, -.142
1295.2, -.143
1288.5, -.142
1283.3, -.142
1276.6, -.142
1265.5, -.141
1257.3, -.141
1251.3, -.14
1245.4, -.14
1242.4, -.139
1237.2, -.138
1230.5, -.137
1225.3, -.136
1223., -.136
1218.6, -.135
1211.9, -.135
1207.4, -.134
1204.4, -.134
1197.7, -.132
1188.8, -.131
1178.4, -.13
1168.7, -.128
1158.3, -.126
1155.3, -.126
1147.1, -.125
1136.7, -.124
1128.5, -.123
1119.5, -.121
1111.3, -.121
1104.6, -.119
1098.7, -.118
1093.5, -.117
1084.5, -.115
1078.6, -.115
1072.6, -.113
1066.6, -.111
1059.9, -.109
1053.9, -.107
1050.2, -.106
1045.7, -.104
1039.7, -.103
1033., -.1
1027.8, -.098
1024., -.095
1019.5, -.093
1018., -.092
1012.8, -.089
1007.6, -.087
1001.6, -.085
997.1, -.083
991.1, -.081
988.1, -.08
985.9, -.079
980.6, -.077
972.4, -.074
967.9, -.072
964.9, -.07
961.1, -.067
959.6, -.067
957.4, -.066
952.1, -.064
948.4, -.062
940.2, -.06
930.5, -.057
924.5, -.054
920.7, -.052
916.3, -.051
909.5, -.048
904.3, -.046
899.1, -.045
893.1, -.044
887.1, -.042
881.9, -.041
876.7, -.04
870.7, -.039
867., -.039
864.7, -.038
862.5, -.038
847.5, -.037
842.3, -.037
838.6, -.036
836.4, -.036
832.6, -.036
828.1, -.036
819.2, -.036
812.5, -.035
808.8, -.034
805., -.033
799.8, -.032
793.8, -.031
787.1, -.029
781.2, -.028
775.9, -.026
771.4, -.025
767., -.024
763.2, -.023
757.3, -.022
752.1, -.022
746.8, -.021
743.1, -.02
739.4, -.02
733.4, -.018
726.7, -.017
719.2, -.015
716.2, -.014
712.5, -.012
709.5, -.011
708.7, -.01
705.8, -.01
703.5, -.008
700.5, -.007
697.5, -.006
692.3, -.005
689.3, -.004
685.6, -.003
681.8, -.002
678.1, .
672.8, .002
669.8, .004
666.8, .006
663.8, .008
660., .01
654.7, .014
651., .017
647.9, .019
643.4, .023
640.4, .026
638.1, .028
635.8, .031
631.3, .035
627.5, .039
624.5, .042
621.5, .045
617.7, .048
614.6, .052
610.1, .057
607.1, .061
604., .065
601., .068
598., .071
594.9, .074
593.4, .078
591.1, .08
590.4, .081
587.3, .085
584.3, .088
580.5, .092
576.7, .097
573.7, .1
570.7, .102
567.6, .105
566.1, .108
562.3, .112
559.3, .116
557., .118
555.5, .121
553.2, .124
550.2, .126
547.9, .128
544.9, .132
542.6, .135
539.5, .139
537.3, .141
534.2, .144
531.2, .148
528.9, .152
525.1, .156
522.1, .16
519.8, .162
516.8, .165
516., .168
512.9, .174
510.6, .18
509.1, .184
507.5, .187
506., .191
504.4, .195
502.9, .2
501.3, .204
500.5, .208
498.9, .212
498.1, .217
495.8, .221
494.3, .225
493.5, .228
492.6, .234
491.8, .237
491., .242
490.2, .245
489.4, .253
488.6, .256
487., .259
484.7, .266
484.6, .275
481.5, .284
477.4, .308
472.4, .343
466.6, .383
463.3, .41
456.5, .467
452.2, .506
448.7, .548
446.5, .592
441.9, .657
437.7, .737
437.3, .801
434.7, .879
431.7, .983
428.2, 1.066
425.1, 1.18
422.8, 1.283
420.5, 1.393
419.4, 1.467