A large and super-rich old tennantite from the classic Zacatecas locality! This was a ridge of matrix that stuck out into the pocket, resulting in its being covered on BOTH SIDES with this pretty combo of milky little quartz crystals and sharp tennantites, the tennantites being beautifully isolated and complemented by the quartz rather than just pressed together in a nebulous mass. Some brassy chalcopyrites add a touch of gold here and there.