The Crown Crescent lode in the Emperor mine has yielded very minor amounts of
bournonite, pyrargyrite, proustite and polybasite.
First came three stunning new
bournonite miniatures found in September 2007 at the renowned locality called Machacamarca: clean, lustrous, satiny gray "cogwheels," each about 5 cm across, are attached at high angles to form clusters devoid of matrix or associated species.
Three
bournonite crystals to 4 mm are seen as floaters in the galena-calcite mixture.
First, Pierre Clavel (minepro@wanadoo.fr) had good
bournonite miniatures from the Mine des Malines, Gard, France.
Until recently the finest examples of
bournonite were those found at the Herodsfoot mine in England over a hundred years ago.
A few scattered rhodochrosites were also on hand, but otherwise it was the same mix of nice Chinese minerals and poor Chinese minerals that we've seen for the last several years: fluorite, stibnite, orpiment, quartz, calcite, broken
bournonite, etc.
Some rare crystals are transparent; others are blue, dark blue, gray or nearly black because of abundant fine inclusions of
bournonite or boulangerite.
Luis reports that the great and renowned Herja mine near Baia Marie, Maramures, finally closed in December 2006, after who knows how many decades of yielding superb specimens of semseyite, stibnite, sphalerite,
bournonite, fizelyite and other sulfides common and rare, as well as fine calcite, gypsum and quartz.
Among the 14 large cabinet pieces here was a matrix plate of fluorite from the Rodderup Fell mine, Alston Moor, Cumbria, with gorgeous, glowing, 3.5-cm cubes of purple/yellow fluorite showing prominent phantoms, on a quartz druse (this specimen is about a foot wide), and, my own favorite specimen, probably, in all the show, a
bournonite from the famed Herodsfoot mine, Cornwall, with a gleaming 3.5-cm metallic black cogwheel rising from amidst others on a 12-cm matrix covered by drusy quartz.
4 and 11); the photos show a 2.1-cm
bournonite crystal with pyrite and sphalerite, and a sphalerite on
bournonite, both in the Ben DeWit collection.