I know you would rather insult others, but perhaps you may want to know that many fossils exist that are not "rock" .
Read, and learn....
TYPES OF FOSSILS
Paleontologist basically recognize two types of fossils:
1. Body Fossils - the actual body or body parts of an organism, whether altered or not.
2. Trace Fossils - any evidence of past life that is not a body fossil; examples: tracks, trails, burrows borings, impressions, molds, casts, steinkerns.
MODES OF PRESERVATION
An important observation to be made about any fossil is the method of preservation. This indicates what happened to the fossil subsequent to its burial, and the kind of environment in which it was originally buried. Not every organism becomes fossilized. Important prerequisites for fossilization are quick burial, and the presence of some hard parts. If the animal is not quickly buried; bacteria, other animals or erosional processes can destroy it. Most fossils have some hard parts. However, organisms sometimes die in anaerobic environments and soft parts can be preserved. But preservation of soft parts is unusual. Below are the different types of preservation.
I. BODY FOSSILS
A. Unaltered Remains--This category includes those fossils which have undergone little or not change in structure and composition. As a general rule (but by no means absolute), an organism which lived fairly recently has a greater probability of being unaltered than a more ancient one.
Original Skeletal Material--Organisms which have hard parts are preserved as the original material. This includes many invertebrate shells composed of calcium carbonate, silica, chitin, or vertebrate bones of calcium phosphate.
Encrustations--In many caves, ground water seeps and drips constantly; the high concentration of dissolved minerals in such water is left behind when the water drips, and forms a thin crust on the interior surface of the cave and whatever lies in it. This will coat and preserve any organism which dies here.
Tar Impregnation--Tar pits are excellent sites for fossilization. The famous Rancho La Brea tar pits in southern California have yielded particularly rich collections of vertebrate bones, wood, etc. Smaller pits have yielded perfectly preserved insects and even insect larvae.
Amber Entombment--Certain cone-bearing trees, such as spruce, pine and fir, contain a sticky resinous "pitch" which comes from wounds in the tree. Small insects and other minute organism may become trapped in this resin, which after burial may harden into amber. Certain parts of the Baltic Sea coast and some of the islands in the West Indies are well known for occurrences of insects preserved in amber.
Refrigeration--During the Pleistocene glaciation, when ice sheets cover much of the Northern Hemisphere, some animals (mammoths, for example) fell into crevasses in frozen terrain or became trapped in permanently frozen soil. Some of these animals have been discovered perfectly preserved.
Mummification--In very arid regions, animals may dry out quickly and be preserved, soft parts and all. Anyone who has found a dried-out fish behind the tank has seen this type of preservation.
B. Altered Remains--As sediments become compressed by the weight of overlying sediments, they slowly undergo the process of lithification. Common cementing materials in the groundwater are carbonate, silica, and iron oxides. Often the groundwater and their minerals may affect the fossilization process.
Permineralization -- Many bones, shells, and plant stems have porous internal structures. These pores may become filled with mineral deposits. In the process of permineralization, the actual chemical composition of the original hard parts of the organism may not change.
Dissolution/Replacement -- Groundwater (especially acidic groundwater) may act to dissolve a hard structure in an organism trapped in sediments and may, simultaneously deposit a mineral in its place--molecule by molecule. Replication of tree trunks, including their internal microscopic cellular structure, by silica in the process of forming PETRIFIED WOOD is a classic example of this type of fossilization.
Recrystallization – conversion, essentially in the solid state, of the mineralogy of the fossil usually to a new mineral or to coarser crystals of the original mineral.
Carbonization -- When organisms become mashed into the sediment, their volatile (liquid or gaseous) components may be forced out, leaving only a film of carbon. If additional organic matter remains when, for example, plants are entombed, the result is coal.
II. TRACE FOSSILS
Mold--Any reproduction of the anatomical features of the internal or external surface of an organism. Animal tracks preserved in rocks may be termed external molds. Internal molds, particularly of shells, are sometimes called Steinkerns. An impression is actually and external mold.
Cast--This is, in general, a duplication of the original. Casts are formed when original parts are dissolved away and the resulting space becomes filled either with sediment or mineral matter.
Compression--In general, this refers to the deformation of a structure as a result of pressure from overlying sediments. This term has been used also for casts and/or molds of leaves.
Borings and Burrows--Certain worms and clams and many other invertebrates burrow into rocks, wood, shells, and all types of sediment. These burrows are frequently preserved, especially in fine- grained rocks.
Coprolites--Fossil excrement can be sometimes give definitive knowledge about the diet of the animal concerned.
Gastroliths--These are smooth, polished stones that are often found in the abdominal cavities of the skeletons of dinosaurs. They are thought to have helped those huge animals grind up vegetable matter in their stomachs.
Gnawings--Rodents and other animals chew on bones for the calcium content and did so in the past. Gnawed bones are frequently preserved as fossils