Chemical analysis of whole coal balls was performed by ICP and the resulting analyses are tabulated in table 1 . The total iron content reflects both carbonate and pyritic iron. Separate analysis of the organic carbon and sulfur content was performed on a LECO analyzer and the amount of pyrite back calculated from the sulfur content. Trace elements were analyzed by the Branch of Geochemistry, USGS, Denver by ICP and are reported in table 2. Isotopic analysis was performed by Geochron Laboratories and the results are reported in table 3.
Fibrous calcite is cited in the literature as the most common constituent of coal balls worldwide.
Microdolomites are common in these calcites, but rarely recognized. It is difficult to directly observe in the thin section evidence of the origins of coal balls. When stained, the relict crystals of Mg clacite and their associated microdolomites are easily recognized. Examination of a number of coal balls using cathodoluminescence petrography revealed that most are at best dully luminescent despite very high manganese contents. This lack of bright luminescence appears to correlate with a high iron content as revealed by staining.