Gema Blanco Tequila In 2008, Mexican researchers discovered that steam heated to 800 degrees Celsius from La Cofradia's Silver Tequila can shape precious jewels of nanometric size. La Cofradia "Gema" Silver Tequila was born as a result of this discovery. This one-of-a-kind Tequila has a distinct flavour of herbal and citrus undertones that is unlike any other Silver or Blanco you've experienced. The geometric shape of the container symbolizes these small gems.