Diamonds have no C14, in spite of what the lead paragraph of your website claims ...
Can this be demonstrated directly? If, for example, the diamond emitted no electrons, then I suppose that would demonstrate it completely. But I don't suppose diamonds are bereft of
all radioactive isotopes capable of undergoing beta minus decay. But perhaps it is still possible to rule out
14C as a source of the radiation by analysis of the emissions; I think this is probably the case, but I don't quite know enough about it.
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