9MF70Q1: Very aerial group of crystals better formed than usual, some of them with very well defined crystalline forms, of good size and luster. This mine operated from 1854 to 1898, producing more than 23 thousand tons of refined copper.
Central Mine, Central, Keweenaw County, Michigan  USA

Specimen size: 3.3 × 3.1 × 1.5 cm = 1.30”