Permineralization

Permineralization is a process of fossilization of bones and tissues in which mineral deposits form internal casts of organisms.

Water from the ground, lakes, or oceans seeps into the pores of organic tissue and forms a crystal cast with deposited minerals.

[2][need quotation to verify] In silicification,[3] the weathering of rocks releases silicate minerals and the silica makes its way into a body of still water.

Often spherical in shape and ranging from a few grams to several hundred kilograms in mass, coal balls are formed when water containing carbonate permeates the cells of an organism.

This type of fossilization yields information about plant life in the Upper Carboniferous Period (325 to 280 million years ago).

[6][7] Permineralized fossils preserve the original cell structure, which can help scientists study an organism at the cellular level.