If the spear head is dated using animal bones nearby, the accuracy of the results is entirely dependent on the assumed link between the spear head and the animal.
They point to a catastrophic origin for granites, consistent with the biblical timeframe for earth history and God’s judgment during the Flood.
When an organism dies, it stops taking in new carbon-14, and whatever is inside gradually decays into other elements.
Carbon-14 normally makes up about 1 trillionth (1/1,000,000,000,000) of the earth’s atmosphere.
Several factors affect radiocarbon test results, not all of which are easy to control objectively.
For this reason, it’s preferable to date objects using multiple methods, rather than relying on one single test.