Petrified fossils is the method of fossilization that preserves the most detail of an organism.
Petrified fossils are formed when minerals replace all or some part of once-living matter. Petrified fossils result from a process known as permineralization which occurs when ground water solutions containing iron, carbonates, silicates or other minerals seeps through the remains of buried organisms (plants or animals). When the water evaporates, the minerals remain and replace the organic matter to form a petrified fossil. This method preserves the most detail of an organism because it greatly retains the appearance of organisms. The growth habits and the actual species of organisms can be identified with this method.
