Mineral(s): Magnetite, ‘Birdseye’ Sphalerite (Fl), Halite/Talc(?) Location: ZCA # 4 Mine, Fowler Ore Body, 2500‘ Level, Balmat, Fowler, Balmat-Edwards Zinc Mining District, St. Lawrence County, New York, USA Size: 5.7 x 3.8 x 3.4 cm Description: This striking specimen has sharp, lustrous cubic and tetrahexahedral magnetite crystals. The crystal edges are crisp, and the symmetry is unmistakable, reflecting magnetite’s isometric crystal system. The crystals stand out for their striking jet‑black coloration and mirror‑like crystal faces that shimmer with metallic brilliance and protrude from a ‘birdseye’ sphalerite matrix that fluoresces under short and longwave UV light. Their association with white halite/talc provides dramatic contrast, enhancing their aesthetic appeal. These stunning cubic crystals are from the ZCA No. 4 Mine in Balmat, St. Lawrence County, a locality renowned for producing some of the finest magnetite specimens in the world. These specimens are no longer being mined and are difficult to find on the market today. High-quality pieces are considered museum-grade. Considered among the finest examples of magnetite morphology, cubic magnetite specimens from New York are prized for their striking geometry, jet-black luster, and rarity among North American minerals. While magnetite typically forms in octahedral shapes, the Balmat specimens often display dominant cube faces, sometimes with subtle tetrahexahedral modifications, making them exceptionally unique. The cubic magnetite specimens from Balmat, New York were discovered in 1991–1992 during mining operations by the Zinc Corporation of America at the Empire State No. 4 Mine (also known as ZCA Mine No. 4) near Sylvia Lake in the town of Fowler, St. Lawrence County, New York. The specimens were uncovered during sphalerite mining in an altered zone containing halite-filled veins.
