They say it holds a secret no less than that of the Universe. That it guards the answer to the power of the Sun. No, it is not the latest Spielberg blockbuster. It is a mine. But a mine covered in a veil of mystery. Alshar, an ancient mine located in the southern Balkans, in Macedonia, is said to contain minerals that are found nowhere else on the planet. The rarest of them allthe lorandite, (TlAsS2 ) a crystal of the thallium. The lorandite is thought to have the potential to unravel the so-called "neutrino puzzle." By serving as a geochemical detector of the neuron, the lorandite could validate or disprove the theory of the standard solar system, say physicists. In simple termsit would let us understand the work of the Sun.