Maria Maria, The Carlos Santana Tequila.
Crystal Tequila is produced by the Casa Noble Tequila Company at the La Cofradia distillery. Casa Noble has been producing Tequila since the mid 1700s in the region of Jalisco, Mexico. They're distinct for distilling the Tequila three times instead of the two times required by law. Moreover, they age Tequila in French Limosin white oak barrels, with the exception of Crystal (which is a Bianco/Silver Tequila).
The Blue Agave they use are left to mature for longer as well - for up to 14 years before they're harvested, unlike most Blue Agave plants that are harvested after "only" 7 years. This helps in the production of a finer spirit. Casa Noble Tequila is endorsed and part-owned by rock legend Carlos Santana.
Casa Noble Crystal is triple distilled organic tequila bottled directly after distillation without any ageing - helping to preserve the Blue Agave flavour and aroma.