Tennantite ex Kay Robertson

Item Description

Tennantite is one of those ore minerals that is always good when in combination with other minerals, and it is highly-desired when found as the main mineral species on a specimen especially when in good crystals like this. The slightly modified tetrahedral crystals here, which number over a dozen, reach an impressive 2.3 cm in size, and the matte-black luster gives the crystals a distinct and weighty look and they are highlighted by a thin film of what may be microcrystalline Calcite. This imposing piece hosts several large crystals and numerous smaller ones that are in excellent condition with most having well-formed faces and edges, but have a sooty appearance as most Tsumeb Tennantites do. The matrix is solid Tennantite and the back of the piece reveals some fresh surfaces that display some blue-gray iridescence. Although the accompanying label for this dramatic piece indicates that it is Tetrahedrite, we doubt that since all of the major references on Tsumeb do not include Tetrahedrite and even state that it is not presence due to the lack of, or at least paucity of, antimony in the system. Acquired from Lidstrom's, this was #10,450 in Kay Robertson's collection and the annotation on her label indicates this is a 'superb' specimen. She acquired it in 1984 from reknowned dealer Walt Lidstrom, her favorite. Valued $1500-2000