A super specimen of rare Chalcophyllite from the St. Day United Mines, an amalgamation of several old mines by 1864, including Wheal Gorland. The specimen consists of a vughy Ferruginous Quartz. Many of the cavities bearing excellent lustrous pearly platy 'hexagonal' crystals of Chalcophyllite, measuring to 0.8cm. Crystals of Chalcophyllite have a luscious emerald green colour. A super crystal specimen of Chalcophyllite from the mines.