Radioactiue inclusions such as zircon, which show a considerable volume increase due to isotropization from radioactiue decay, often fracture the surrounding mineral in a random pattern. On uniformitarian concepts the surrounding mineral should expand slowly over geologic time. Expansion cracks should occur first along cohesion minimums and grain boundaries, but instead individual cracks surrounding the radioactive inclusion are randomly distributed and occur suddenly, in an explosive fracture. Anomalous decay rates would explain this world wide phenomena. Mathematical equations showing the relationships involved in pleochroic halos are given.