Yes, carbon-14 (C14) can indeed be found in natural diamonds, though typically in extremely small quantities. The presence of this radioactive isotope is not due to the diamonds forming from conventional carbon sources containing C14, but rather from a unique process occurring within the diamond itself.
How Carbon-14 Forms in Diamonds
Natural diamonds are renowned for their purity, but they are not entirely composed of carbon. A common and significant impurity found in natural diamonds is nitrogen, which can constitute as much as 0.1% of a gem-quality diamond's mass. This nitrogen is primarily in the form of nitrogen-14 (N14), the most abundant isotope of nitrogen.
The formation of carbon-14 in diamonds occurs through a process known as neutron capture:
- Nitrogen Impurity: Diamonds contain nitrogen-14 atoms incorporated into their crystal lattice during formation.
- Neutron Exposure: When these nitrogen-14 atoms are exposed to neutrons, they can capture a neutron.
- Transmutation: Upon capturing a neutron, the nitrogen-14 atom undergoes a nuclear reaction, transforming into carbon-14 and releasing a proton. This process is represented as:
N14 + n → C14 + p.
This mechanism is similar to how carbon-14 is produced naturally in the Earth's upper atmosphere, where cosmic rays generate neutrons that interact with atmospheric nitrogen. Within the Earth's crust, the neutrons required for this reaction can originate from the radioactive decay of elements like uranium and thorium found in nearby rocks. While the rate of C14 production in diamonds through this method is significantly lower than in the atmosphere, it is sufficient to explain the detectable presence of carbon-14 in these ancient geological formations.
Implications of C14 in Diamonds
The carbon-14 detected in diamonds is therefore in situ (formed within the material itself) rather than being incorporated from external sources during the diamond's initial formation. This means that its presence does not contradict the vast geological ages typically assigned to diamonds. The C14 is a product of ongoing nuclear reactions involving impurities and ambient radiation, not a remnant of the carbon's original isotopic signature from millions or billions of years ago.
For further information on the presence of carbon-14 in diamonds and related scientific discussions, you can refer to discussions on the topic from reputable scientific communities, such as those found on platforms like Reddit's r/askscience forum: C14 in Diamonds: evidence of a young earth? : r/askscience - Reddit
