Superb plate completely covered with excellent 1 cm Bournonite crystals intermixed with a small amount of well-crystallized pyrite. The Bournonites have striated faces with a silky to mirror-like metallic luster, and the terminations show the same variation in luster. You can see the development of Bournonite's classic cogwheel habit. this is a MAJOR Mexican bournonite specimen. It is old, fine, and large - with also large crystals for the locale.