Unconvinced, this is from the article you linked to:
Going back to Gentry's early research (Gentry 1968, 1971; Gentry et al., 1973), it is apparent that the association of concentric colored haloes with polonium is actually very speculative. Rather than provide conclusive experimental evidence, Gentry simply adopted the conclusions of Joly (1917) and Henderson (1939) that polonium isotopes were the most likely culprits for the features observed. No empirical evidence is given that the concentric haloes without observable central inclusions are even due to radiation damage. His entire thesis is built on a compounded set of unproven assumptions.
A lot of what you and others accept in science have "no empirical evidence" to establish there accuracy.