Choice, lustrous and quite rare, fine Sphalerite from the famed Neudorf Mines. This locale was worked for Silver and Lead mostly in the 18th century and closed in 1903. The mine is renowned for some of the world's best Galenas and Bournonites from that era which are among the world's great mineral treasures. Sphalerite however is far more rare from this locality, and good examples are almost never seen. This piece has a main crystal just under 2 CM in size, the Siderite is crystalized as yellow to brown rhombs and makes a nice contrast. The Sphalerites are mostly a lustrous black but at the right angles there are bright flashes of red color. A fine and very old miniature of this classic locale.
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.
Blue-green Fluorite crystals reaching 3.3 CM with several distinct Siderite crystals on and between the Fluorites. A nice old German piece with labels from A. Kranz and another earlier collection, this is in very good condition overall. This locality was worked for a very long time and finally closed about thirty years ago, though we believe this specimen is at least 100 years old. The Siderites are in well-formed lath type crystals and show curved faces much like Dolomites. A classic piece from the southern Harz Mountains, we rarely see specimens from this locale here in the USA, this one is well better than average.
Native Silver (Sheet form)
Eisleben, Mansfeld Basin
7.6 x 2.6 x 1.9 CM (cabinet)
One of the more odd forms of Silver are these thin sheets, almost like a Silver foil found in narrow seams of Slate. Very old material, these were mostly extracted in the early 1900's, the locality is a German classic. The Slate matrix is Copper bearing which is an unusual host for Silver anyplace. The Silver leaf is partly peeling from the matrix and shows the delicate form, being under .05MM thick.
The Eisieben Mines date back to the end of the 19th century (or more), worked for Copper and Nickel, but from time to time some excellent Selenite was found. This is a choice piece, in pristine condition, with sharp delicate prisms on matrix. In person the transparency is far more impressive.