Dims: 6.2" x 2.5" x 2.5" (15.7 x 6.4 x 6.4 cm)
Wt: 2 lbs., 9.9 oz. (1.189 kg)
Uruchacua Mine, Ancash, Peru
This specimen consists of scores of cubic Pyrite crystals that have intergrown to form a crust. These crystals range from 3 mm to about 1.0" (2.5 cm) along an edge. They are in very good condition, generally, with a small amount of damage, and clean edges and faces that have noticeable uniform, parallel striations running across them. They have the standard pale golden color and metallic luster of Pyrite, and occur in a section of crust that contains small hollow pockets that are lined with more crystals. The underside of the section also has many visible crystals, though most of them are damaged and incomplete. Besides the Pyrite, there are many tiny, barrel-shaped calcite crystals nestled among the cubes on the specimen's underside, and several large and impressive siderite crystals among the larger cubes on the top of the section. The calcites are white colored, the siderites are pale brown, and both are translucent and have a pearly luster. Though I have looked at this specimen many times before, I never noticed those siderite crystals until I just examined it to write this description.