Pyrolusite

A very fine and beautifully crystallised Pyrolusite from the Eisenzecher Zug mine at Eiserfeld in North Rhine-Westphalia, Germany.  Spiky, bladed black metallic crystals of up to 1.7 cm tall cover 60% of a matrix built from granular Pyrolusite covered with sub-3 mm Pyrolusite crystals.  All the crystals have a bright, highly reflective lustre and at one end are bordered by a ring of tiny, milky-white Quartz crystals.  A very fine example of Pyrolusite, a mineral composed almost entirely of manganese dioxide.  The specimen is accompanied with an old label with copperplate handwriting.