The accompanying atlas of coal petrology provides about 300 images of macerals and of minerals in coals. The geographic coverage, while worldwide, emphasizes the coals and regions the authors study most frequently. Images of unique maceral and mineral assemblages are provided. The lack of images from certain regions should not be considered to reflect a lack of coverage of those coal types as, at the most basic level, many of the images can be considered to be "generic" maceral images. An emphasis on lower rank, primarily high volatile A bituminous and lower, coals is evident in the collection of images. The visual contrast among individual macerals is greatest within these ranks. In addition, much of the world coal trade is conducted using the bituminous and lower rank coals.
Wherever possible, the images are accompanied by coal bed, location, age, and rank information. While each piece of information is important in documenting the source and rank context, the information provided should not be construed as implying that the image is necessarily typical of macerals in that coal bed, from that area, of that age, or of that rank.
We trust that this atlas will prove to be useful to both experienced coal petrologists and as well as to others who are seeking an understanding of the variety of macerals present in coal.