A major, important antique German Bournonite in a large single crystal. Certainly not pretty but reputed to be the the biggest known single crystal from this famed locale and possibly the largest single crystal from all of Germany. This is also quite sharp for the size at the locale. Over 6 CM across, this is a flat tabular habit as is typical from the Georg Mine. Rather crude in some areas but very sharp in others, it has a few contacts but overall is quite distinct as seen. The vintage Boubée label dates this to late 1800's to early 1900 era, so collected at least over 100 years ago, likely much older. Some faces show an interesting metallic patina and in person there is a fine "gunmetal" luster in spots.
A superb classic thumbnail specimen from the famed Neudorf area, best known for world-class Galenas and rarely some great Bournonites. In flawless undamaged condition. These Bournonites are bright, lustrous metallic crystals on a matrix of sparkling white Quartz that is also the host for fine Siderite crystals. This can be displayed in several orientations, it is almost impossible to find a choice thumbnail like this from Neudorff today. A few earlier labels are included, this sort of specimen is certainly very old.
A cabinet sized cluster of intergrown Bournonite crystals with a scattering of sharp, lustrous Sphalerites. This is not from the famed region of Les Malines in Gard, well-known as a major classic locality for Bournonites, this specimen is from an unusual locality at Saint-Laurent-le-Minier which is also in Gard. Mindat list this as a source of Bournonite but has no examples pictured. These crystals are up to 2.6 CM and are covering almost the entire specimen. These have a dark patina, some edges show classic cogs-wheel form but most are prismatic and well-defined. The Sphalerites are a mixture of lustrous black and red-orange crystals some of which are transparent. The minerals coat the matrix everywhere except for a small spot on the underside. A choice French Bounonite with a little different look than the usual more metallic specimens. Ex John Marshall collection obtained by him in 1969.
Yaogangxian Mine, Yizhang County, Chenzhou Pref.
3.1 x 2.6 x 1.5 CM (small miniature/ large thumbnail (toenail))
new year 2021
A super bright "gun metal" luster Bournonite crystal which is doubly terminated. Some of the faces are perfectly smooth mirror-like while other are striated. From the Yaogangxian Mine which had the reputation for providing more fine Bournonite than the rest of the world's localities together. Before these finds this was a rather rare and sought after specie. There seems to be no twinning on this crystal which is unusual for Bournonite which is almost always twinned. Displays well as seen, there are some small chips on the terminations and the back is contacted but not damaged. While not perfect this is far better than 99.9 percent of these, and the rough areas are not excessive. As a whole Bournonites are notoriously brittle and most often incomplete.
Bournonite is so often twinned or in classic "cogs-wheel" form that untwinned crystals are quite rare. This Quiruvilca (Peru) specimen is that unusual sort, here are many Bournonite crystals, some over 1.2 cm but no twins. In fine condition overall most crystals are perfect but with good magnification some small areas of rough edges are found. For this notoriously fragile specie that is impressive. Some bright golden pyrite adds contrast to the dark silver-metallic Bournonite. For some reason the Pyrite at Quiruvilca Mine is often especially bright and lustrous, it seems to be more stable than most and keeps the bright golden color much better than any other Pyrite I know. A fine addition to a serious Sulfide collection.
Bournonite with Quartz
Yaogangxian Mine, Yizhang County, Chenzhou Pref.
6.5 x 4.7 x 3.8 CM (cabinet)
A cluster of large Bournonite crystals that are complexly intergrown with only a single Quartz crystal as matrix. Ex Shields Flynn Collection, this has the fine "gun-metal" luster that is most desirable from Yaogangxian Bournonites. Some crystals exceed 3CM and show flat terminations and classic cogswheel form twinning. In very good condition despite some small bruises this is in far better condition than most. This specimen was displayed in the Tucson show special exhibit on Chinese minerals. This was an early (2000's vintage) obtained by Shields from Bert Ottens in the golden years of Chinese mineral finds.
We see very few Bournonites from Trepka and almost never of good esthetics. This is a very pretty specimen with the best quality we have ever seen. The most prominent Bournonite crystal is perfect, undamaged 1.4 CM in diameter and has bright metallic luster. It is a textbook quality twin with cogswheel form on the edges. The whole piece has choice contrast with brilliant Pyrite forming most of the matrix. Trepka has been known as an excellent source of other Sulphides. This new find was small but had impressive Bournonites which is certainly newsworthy and exciting.
Bournonite, Quartz and Pyrite
Pachapaqui District, Bolognesi Province
7.2 x 5.4 x 5.2 CM (cabinet)
Late Summer 2018
Two-sided specimen with excellent sharp Bournonites on both sides. All the Bournonites show bright silver luster and twinning that in some crystals has the classic cogswheel habit. The side I consider the "front" or better display side has two main Bournonites that are perfectly formed and undamaged, set off by golden Pyrite and milky Quartz crystals. The "back" side has more nice Bournonites but there is some damage and contacts, (that is why it is the back of course). A few years ago matrix Bournonites of this quality were very rare and expensive when available but both China and Peru then began to produce these and they became very affordable. Now both these sources are not producing.