Brandtite with Caryopilite, Rhodonite, Hausmannite, Magnetite - image 1

Brandtite with Caryopilite, Rhodonite, Hausmannite, Magnetite

Unknown Owner

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Superb example for this rare species with colorless platy crystals of brandtite across the top of a matrix with crystallized caryopilite, rhodonite, hausmannite, and magnetite. In great condition. The specimen comes with an antique label as shown at the end of the video. The original acquisition date for this piece was in 1911. The Harstigen mine, situated near Pajsberg in the historic Filipstad mining district of Varmland, Sweden, was a small but mineralogically extraordinary underground iron and manganese operation. Geologically, the deposit belonged to the classic Langban-type mineralization style, characterized by a highly complex, metamorphosed stratabound deposit hosted within Paleoproterozoic-age supracrustal metavolcanic rocks and dolomitic marbles. Intense regional metamorphism and subsequent hydrothermal activity acting upon localized manganese-iron lenses triggered the development of an unparalleled suite of rare lead-manganese silicates, arsenites, and antimonates, yielding dozens of distinct mineral species including sarkinite, harstigite, and flinkite. Historically, small-scale exploratory mining and open-pit quarrying began at the site in the early nineteenth century, but formal underground shaft sinking and systematic exploitation occurred primarily during a highly productive operational window between 1847 and 1887. The mine was worked principally for its high-grade manganese ore until persistent groundwater flooding and the limited physical dimensions of the ore body made deep-level extraction economically unfeasible, leading to the permanent closure and abandonment of the underground workings in 1887. Brandtite is a rare hydrated calcium manganese arsenate mineral that crystallizes in the monoclinic system. Geologically, it occurs as a highly specialized secondary mineral within complex, metamorphosed iron-manganese deposits, typically forming in late-stage hydrothermal veins and fractures that cut through pre-existing manganese ore bodies. The primary historical type locality for this mineral is the famous Harstigen mine near Pajsberg in Varmland, Sweden, where it was first discovered and described in 1888 by the Swedish mineralogist Hjalmar Sjogren, who named it in honor of the prominent chemist Georg Brandt. In this classic geological environment, the mineral typically developed as distinct, colorless to white, radiating acicular prisms, tufts, or fibrous aggregates closely associated with other rare species like sarkinite, flinkite, and manganiferous calcite. Because it requires a highly specific geochemical environment rich in both arsenic and manganese but low in silica, brandtite is found at only a handful of localities worldwide. Dr. Ludwig Eger (active c. 1870-1915) was a highly respected Austrian mineral dealer based in Vienna who played a significant role in the distribution of Central European and Alpine mineral specimens during the late 19th and early 20th centuries. Operating under the firm name "Dr. L. Eger," his business was situated in the heart of Vienna, a primary hub for scientific exchange during the Austro-Hungarian Empire. Eger was noted for his professional, academic approach to the mineral trade, often supplying high-quality, systematic collections to universities and major museums throughout Europe and North America. His labels are easily recognized by their classic 19th-century typography, typically featuring "Dr. L. Eger, Wien" (the German name for Vienna) and providing detailed locality and species data in a formal, structured format. In addition to minerals, Eger dealt in paleontological and zoological specimens, as was common for the natural history establishments of the time.