An outstanding acanthite miniature from the La Sirena Mine (590 Level) at Guanajuato. Lustrous, battleship-gray, blocky to extremely elongated, cubic acanthite crystals comprise this striking, arborescent crystal cluster. A pristine, complete-all-around acanthite from Guanajuato. Even the mine level is known. Classic material. The back of the piece looks like a cluster of feathers.