Electron spin resonance dating, or ESR dating, is a technique used to date materials which radiocarbon dating cannot, including minerals (e.g. carbonates, silicates, sulphates), biological materials (e.g., tooth enamel), archaeological materials (e.g., ceramics) and food.[1] Electron spin resonance dating was first introduced to the science community in 1975, when Japanese nuclear physicist Motoji Ikeya dated a speleothem in Akiyoshi Cave, Japan.[2] ESR dating measures the amount of unpaired electrons in crystalline structures that were previously exposed to natural radiation. The age of a substance can be determined by measuring the dosage of radiation since the time of its formation.[3]