The Natural History of Gemstones Prof. B. Dutrow Nature's handy work in the making of gems is no less dazzling than their appearance. Contained within gems are clues to the prehistory of our planet. Tourmaline records mountain building episodes, the chemistry of magma chambers and the composition of fluids that flow through the Earth's crust. Rapidly changing pressure, temperature and compositional conditions are forever encased in the composition of a single tourmaline. In contrast, diamonds provide insights into the chemistry and composition of the Earth's mantle and the unique conditions that occur at depths of 120 - 190 km below the surface.
Diamonds record a fascinating history of creation and survival through ca.
160 km of high speed transport to the surface. This presentation will highlight the genesis of diamonds and tourmaline, their transportation to the surface, the environmental conditions that they represent and their survival though the millenia to ultimately give us some of the most prized gemstones on Earth.