Hambergite

specimen number:
1052598

location:
Imalo, Andrembesoa, Betafo, Vakinankaratra, Madagascar

description:

An impressive huge crystal for the species. This is a loose semi lustrous translucent colorless crystal of hambergite. In good condition all around with very minimal micro-damage present. Originally acquired through the American dealer Lazard Cahn in 1911. The specimen comes with an antique label as shown at the end of the video. There is also a hand written letter to Mr. Gruson from the Munich dealer A. Kusche that accompanies the specimen. These are shown at the end of the video. While somewhat aesthetically challenged, I cannot recall ever seen such a large crystal for the species and I believe this to be very rare.

The Imalo commune, situated within the Mania Region of the central highlands in Madagascar, is a world-renowned mineral locality celebrated for producing exceptional, sharp, and highly translucent crystals of the rare beryllium borate mineral hambergite. Geologically, these unique crystals are hosted within highly evolved, late-stage granitic pegmatites belonging to the pan-African Sahatany Pegmatite Field, which intruded Precambrian-age metamorphic basement rocks during the Cambrian period roughly 500 million years ago. Intense fractional crystallization within these boron and beryllium-rich magmatic fluids created large miarolitic cavities, providing the ideal low-pressure environment for pristine, white to colorless, vertically striated hambergite prisms to crystallize alongside multi-colored tourmaline, spodumene, lepidolite, and quartz. Historically, the area has never been exploited by massive, high-capacity industrial underground mining corporations; instead, specimen extraction has been carried out almost entirely through small-scale, localized open-cast quarrying and manual pit-digging by artisanal miners or local cooperatives. Organized gem and mineral specimen mining in the Sahatany and Imalo zones escalated significantly during the early twentieth century under French colonial rule, with sporadic, highly productive spikes in hambergite discovery occurring from the 1990s through the 2010s as miners chased deep pegmatite pockets.

Lazard Cahn (1865-1940) was a prominent American mineral dealer and self-taught crystallographer based in Colorado Springs who became one of the most respected figures in the field during the late 19th and early 20th centuries. He was widely recognized for his exceptional ability to identify rare species and for his meticulous study of crystal forms, eventually having the borate mineral cahnite named in his honor. Cahn operated a high-end mineral dealership that catered to major museums and elite private collectors, specializing in rare alpine minerals and classic American localities. His professional career was marked by significant contributions to mineralogical literature, including his work on the micromounting of specimens and his detailed descriptions of complex twinning laws.

Arthur Kusche, operating out of Munich (Muenchen), Germany, during the early twentieth century, was a prominent mineral dealer who supplied high-quality regional and international specimens to notable European and global private collectors, academic institutions, and museums. Registered commercially as Arthur Kusche GmbH, his dealership functioned alongside other well-known contemporary Munich firms like Wilhelm Maucher and the Mineralogisches Institut, actively sourcing choice mineral specimens during the peak of central European geological exploration and mining activity. Geologically and historically, Kusche was instrumental in preserving and documenting the provenance of classic alpine, Scandinavian, and eastern European mineralized deposits, acquiring specialized pieces from legendary localities such as the silver mines of Freiberg, the polymetallic systems of Romania, and regional German pegmatites. Historical archives, museum catalogs, and acquisition logs from institutions like the Royal Scientific Society in Trondheim and the State Geological Museum of Lausanne confirm his commercial activities were highly vibrant throughout the 1910s and 1920s, showing that he routinely curated, cataloged, and sold pristine specimens embedded in calcite, quartz, and fluorite gangue matrices.

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