Outstanding, large cluster of significant Cuprite crystals, many of which are modified octahedrons. The Cuprites range up to 1.3 cm, with the average around .8 cm. They have an oxide coating, but are still capable of glowing red as they transmit light. The Cuprites are on a Copper matrix, with the crystal form frequently well-defined on many of the crystals. This HAS TO BE one of the better Cuprite specimens from Butte - though I have seen no others to compare it to. Formerly in the collection of the famous collector Ed Swoboda, this has a competition label tag with it from one of his exhibits, and by Kay's accession number dates to the 1970s (when the mine was producing). A rare old USA specimen!