The method assumes, among other things, that the earth's age exceeds the time it would take for C-14 production to be in equilibrium with C-14 decay.
In theory, it might be useful to archaeology, but not to geology or paleontology.
Furthermore, the assumptions on which it is based and the conditions which must be satisfied are questionable, and in practice, no one trusts it beyond about 3,000 or 4,000 years, and then only if it can be checked by some historical means.
But, carbon dating can't be used to date either rocks or fossils.
It is only useful for once-living things which still contain carbon, like flesh or bone or wood.
Carbon can bond to itself and forms an enormous number of important molecules, many of which are essential for life. The two most familiar forms of carbon—diamond and graphite—differ greatly because of the arrangement of their atoms.
In diamond, each carbon atom bonds to four others in a dense network that makes the material the hardest substance known.In 1985 an entirely new form of carbon was discovered in which carbon atoms join to make a sphere called a buckminsterfullerene or buckyball, after Buckminster Fuller, who created buildings with a similar appearance.Perhaps no concept in science is as misunderstood as "carbon dating." Almost everyone thinks carbon dating speaks of millions or billions of years. Symbol C An abundant nonmetallic element that occurs in many inorganic and in all organic compounds, exists freely in amorphous, graphite, and diamond forms and as a constituent of coal, limestone, and petroleum, and is capable of chemical self-bonding to form an enormous number of chemically, biologically, and commercially important molecules.Other significant allotropes include fullerenes and nanotubes.Obviously, if half the C-14 decays in 5,730 years, and half more decays in another 5,730 years, by ten half-lives (57,300 years) there would be essentially no C-14 left.