Cantera Negra translates as "black quarry rock," presumably named for the black, volcanic rock of Jalisco, Mexico. The Cantera Negra Reposado ("rested") tequila is aged for "almost an entire year," suggesting something on the order of 11 months (12 would give it an "anejo" designation). This may give it a slightly darker color and more oak-driven flavor than other reposado tequilas aged for a briefer period of time.
The brand takes special pride in carefully selecting the agave plants and aging a portion of their tequila in their own oak barrels (the rest aged in the more common method of ex-bourbon barrels).
Cantera Negra tequila is a brand founded by Don Alberto Becherano and imported into the United States by Two Sons Imprts. The distiller is Cavas de Don Max, who lay claim to the ability to call their tequila "elixir de agave."