Large and with textbook perfect form, this is a killer old German Selenite ex. Lazard Cahn, Charles Noll and others. Lazard Cahn (1865-1940) had a long and highly regarded career as a mineral collector and dealer. His label is vintage 1908-1940, the mine itself is even older, type locale for two species and a classic locale by any definition. The Gypsum is fully transparent, sharp and internal structures and clouds can be clearly seen inside. From some angles the internal structures seem to show a phantom but it is faint. The main crystal twin is doubly terminated and looks fine from any angle but the second photo shows the best view in my opinion.
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.