Principle of Radiocarbon (C-14) Dating
Carbon exists in three isotopic forms: carbon-12, the most abundant in the atmosphere, carbon-13, and carbon-14 (C-14), which is radioactive.
The method of radiocarbon dating (C-14 dating) consists of measuring the proportion of radioactive carbon-14 relative to the two stable isotopes in a sample of organic material (such as fibers, wood, bone, or ivory) that once participated in the natural carbon cycle.
While an organism is alive, the relative concentration of C-14 remains constant due to respiration, feeding, photosynthesis, and other exchanges with the biosphere. After death, these exchanges stop and the level of C-14 decreases by half every 5,730 years (the half-life of carbon-14). Measuring the residual amount of C-14 therefore allows scientists to determine the approximate time of death of the organism — up to about 50,000 years.
Applications in Art and Archaeology
Organic materials such as bones, teeth, shells, tissues, wood, or ivory can all be dated using radiocarbon (C-14) analysis.
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In the art market and authentication of artworks, this method can determine the maximum age of an object made from organic materials (canvas fibers, wooden supports, ivory sculptures) and verify whether it matches its claimed period or provenance.
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In archaeology, radiocarbon dating helps reconstruct the chronological history of sites and cultural layers.
Measurement Process
To perform C-14 dating, a sample (ranging from micrograms to a few grams) is carefully extracted from the object. Through a series of chemical and physical treatments, only the carbon content is isolated.
The concentration of carbon-14 is then measured using an accelerator mass spectrometer (AMS), which separates atoms by their mass and charge, and compares them with reference standards. This provides a specific radiocarbon age of the sample.
At the same time, the stable isotope carbon-13 is also measured, providing insights into the diet and environment of the organism.
Finally, the radiocarbon age is calibrated against standard calibration curves to convert the relative age into a calendar age, allowing accurate dating of the object’s origin.