A taste challenge! Both are Maguay Espadín mezcals.
Monte Alban- introduced in 1977. 80 proof. Produced for Barton Imports.
https://www.sazerac.com/our-brands/sazerac-brands/monte-alban.html
Xicaru Silver- introduced in 2013. 81 proof. A Xicaru brand.
https://xicarumezcal.com/brands/mezcal/xicaru-silver-mezcal/