There are three subgroups of permineralizations: silicification, pyritization, and carbonate mineralizations.
As with almost all fossilization processes, silicification (because of its conditions for fossilization) tells us much about what type of environment the organism was likely to live in. Specific fossil types occur in environments with certain features. Silicification is a fossilization process whereby the organism is penetrated by minerals that form on the cells and cell structures. In this case, the mineral is silica, and because the mineral "follows" the internal structures of the organism during mineralization. This accounts for the amazing amount of detail found in permineralizations. For example, (for silicification) fluids in volcanic terrain often contain silica that could be absorbed by the plants themselves. This would indicate that a volcano was near the plant in the past. An interesting point that this example presents is that the plant was already beginning its fossilization process when it was still living. The silica that is taken up by the plants become embedded within them and when they die, the material (silica) is already present within them to quickly mineralize the organism and fossilize it. In this way, the silicification process can often show very fine detail.
Pyritization involves the mineral sulfur. Many of the plants are thus pyritized when they are in marine sediments since they often contain a large amount of sulfur. This could have been their natural habitat in the past or they could have been near enough to a marine environment to end up there to be pyritized (after being carried down by a river, flood, or some other method). Some plants are also pyritized when they are in a clay terrain, but to a lesser extent than in a marine environment.
Carbonate mineralizations occur both in marine and nonmarine environments. The most popular forms of carbonate mineralizations that are cited in biology are what are called "coal balls." Coal balls (which are often found in a round ball shape, which gives them their name) are often a fossilization of many different plants and their tissues. Often, they occur in the presence of seawater or acidic peat. Acetate peels can also usually be made to study the various organic material trapped within a coal ball. These peels may sometimes be fairly revealing of cellular detail.
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