Professor Willard Libby produced the first radiocarbon dates in 1949 and was later awarded the Nobel Prize for his efforts.
The uncalibrated date is given with the unit BP (radiocarbon years before 1950).
Although a family heirloom is less likely to be forged than a purchased weapon, the possibility always exists.
Some foreign firearms have been replicated for centuries, specifically for the tourist trade.
Isotopes of a particular element have the same number of protons in their nucleus, but different numbers of neutrons.
This means that although they are very similar chemically, they have different masses.From these records a “calibration curve” can be built (see figure 2, below).