2 pc 23.30 ct HEDENBERGITE – USA

Hedenbergite Hedenbergite is a mineral that speaks to the raw, transformative power of the earth’s interior. As an iron-rich member of the pyroxene group, it lacks the bright, commercial colors of other gems, but it makes up for it with a deep, forest-green to near-black intensity that feels incredibly grounded. I have always been drawn to its structural elegance, especially when it forms as radiating, prismatic crystals. When we find material that is translucent enough to facet, it produces a gemstone with a brooding, sophisticated character. It’s a stone for the collector who finds beauty in the dark, "industrial" aesthetic of the silicate world—a gem that looks like it belongs in the vault of a master mineralogist. The Heritage & Discovery Historical Significance: Hedenbergite is a vital indicator of "skarn" deposits—environments where limestone has been baked and chemically altered by nearby magma. It represents a specific geochemical threshold where iron and calcium dominate the cooling process. For centuries, it has been studied not just for its own sake, but as a roadmap for miners seeking the rich deposits of copper or lead that often hide alongside it. Discovery: The mineral was first described in 1819 and named by the Swedish chemist Jöns Jacob Berzelius in honor of Ludwig Hedenberg. Hedenberg was a Swedish chemist and mineralogist who was the first to identify the mineral as a distinct species during his studies of the Swedish mining districts. Important Mines: The most exceptional specimens, often forming the iconic "radiating" clusters, come from the Dalnegorsk region in Russia. Other world-class crystals have emerged from the Nordmark region in Sweden and the Island of Elba, Italy. For facet-grade rough that allows for a glimpse of that deep green translucency, I keep a close watch on the skarn deposits in Mexico and the Mogok region of Myanmar, where rare, gemmy fragments occasionally surface. Mineralogical Profile Description: Hedenbergite is a calcium iron silicate and an endmember of the pyroxene group. It crystallizes in the monoclinic system and sits at a 5.5 to 6.5 on the Mohs scale. It features a vitreous to dull luster and a characteristic dark green to brownish-black color. Because it forms a solid solution series with diopside, the exact iron-to-magnesium ratio determines its final appearance; the more iron present, the darker and more "Hedenbergite-rich" the stone becomes. It possesses the classic pyroxene cleavage, which requires a precise and steady hand during the faceting process to avoid "stepping" on the polish. Chemical Formula: CaFeSi₂O₆