Permineralization is a way in which a plant or animal can be fossilized.
Permineralization is one of the ways in which a plant or animal can be fossilized. During this process, mineral-rich water seeps into the empty spaces of an organism, leaving mineral deposits that slowly build up, creating a mold of the organism. In some cases, the entire plant or animal can be turned to stone in this way, in which case the resulting fossil is considered petrified. Many museums have examples of fossils that have been preserved using this method, and people can sometimes find these fossils for sale at stone stores and hobbyist stores as well.
Fossils are the result of permineralization.
This process is very unusual. Billions of organisms have died on Earth throughout geological history, and only a fraction of these organisms have been fossilized because nature has developed a very elegant and efficient system for recycling dead plants and animals. For permineralization to occur, an organism must be rapidly covered by sediment soon after death. Many petrified fossils are marine organisms that fell to the ocean floor and were covered by sediment.
Examples of permineralization can be found in coal mines.
The permineralization process is very slow. It happens when water seeps into the sediment covering an organism; the sediment helps keep the organism intact and the mineralized water slowly seeps into the debris. Depending on the type of minerals involved and the conditions, petrification can result in incredibly detailed preservation, allowing people to differentiate individual cells in the organism, or it can create a rougher mold.
When permineralization involves sulfur, it is called pyritization.
When petrified fossils mostly contain silica, archaeologists say they have undergone silicification. Silicification is an excellent preservation technique that sometimes retains immense detail. When sulfur is involved, the process is called pyritization. Pyritization occurs most commonly in marine organisms. You can also find some excellent examples of carbonate mineralization in places like coal mines.
During the petrification of wood, cellulose and living tissue are replaced by minerals.
In many cases, permineralization only preserves the body’s mineral tissue, such as bones, teeth, and shells. In other cases, it fills a void left in the sediment by an organism that has since rotted away; this usually happens with fossilized leaves. In very rare cases, some or all of the soft tissue is preserved, allowing people to catch a glimpse of a body that could be millions of years old to learn more about how it works.