The Tethys Theory of Ruby Formation

  by Angela Magnotti Andrews The most prominent theory to explain the geological marvel of ruby formation carries as many mysteries as rubies themselves. It is believed that Himalayan rubies began their journey in the ancient Sea of Tethys. The Tethys Sea is said to have once rested between the continent of Asia and the subcontinent of India, at a time when the world's topography looked remarkably different than it does today. Experts suppose that "dirty" limestone, deposited by the erosion of surrounding rocks and land, covered the ancient sea's floor. This limestone contained all the elements required for ruby formation. However, it also included vast amounts of the one element which inhibits the growth or rubies: silica. Geologists not only attempt to answer the question of how exactly the Tethys Sea became what we now know as the Himalyan Mountains, but they must also tackle the mystery of what became of the silica. These masterful scientists of the earth conclude that as India and Asia came together in a tectonic collision of massive proportions, the pressure drove the limestone floor of the Tethys Sea down toward the center of the earth. Here, where temperatures exceeded 1200 degrees Fahrenheit and pressures rose as high as 6 kilobars, they believe that the elements metamorphosed into the cohesive form we call marble. Simultaneously, they propose, flows of molten granite intruded into these bands of marble, carrying away that nemesis of ruby formation: silica. As the waters continued driving the two land masses together, the Himalayan Mountains erupted forth, jealously guarding their precious cache until succumbing to wind and water erosion, which later exposed the intermittent bands of scarlet ore. BIBLIOGRAPHY 1. Sasso, Anne. "The Geology of...Rubies." Discover Magazine (November 2004). Published online November 25, 2004. http://discovermagazine.com/2004/nov/geology-of-rubies. 2. Smigel, Barbara. "Ruby July's Birthstone." Gem Society. Accessed May 15, 2012. http://www.gemsociety.org/info/gems/Ruby.htm. 3. Want to Know It? "How Rubies are Formed." Accessed May 15, 2012. http://wanttoknowit.com/how-are-rubies-formed/.