3.00 ct KUTNOHORITE – USA

strong>Kutnohorite

Kutnohorite is a gemstone that captures the delicate, structural elegance of the rare carbonates. A member of the Dolomite group, it is a calcium manganese carbonate that often presents in the most beautiful “saddle-shaped” crystals or rounded, cauliflower-like aggregates. I have always been moved by its soft, “petal-pink” to creamy-white hues; there is a gentleness to its color that feels remarkably organic. While it is rarely transparent enough for traditional faceting, I have seen exceptional specimens with a pearly luster that makes them glow like fine porcelain. It is a mineral of transition and balance, representing the point where calcium and manganese meet in perfect, rhythmic symmetry. For the collector, it is a stone of refined beauty that brings a touch of “shabby chic” elegance to the mineral cabinet.

The Heritage & Discovery

Historical Significance: Kutnohorite is an important mineral for understanding the chemistry of manganese-rich sedimentary and hydrothermal environments. Historically, it has been a significant find in ancient mining districts where silver and base metals were pulled from the earth. It represents a specific geochemical “middle ground” between Dolomite and Ankerite. In the world of fine minerals, it is celebrated for its unique crystal habits—particularly the “saddle” shapes caused by its slightly curved crystal lattice. It stands as a sophisticated representative of the carbonate family, bridging the gap between common rock-forming minerals and rare, colorful collector’s pieces.

Discovery: The mineral was first described in 1901 and was named after its type-locality: Kutná Hora in the Central Bohemian Region of the Czech Republic. This historic silver mining town has been a hub of geological activity for centuries, and naming this elegant pink carbonate after such a legendary location was a fitting tribute to the region’s rich mining heritage.

Important Mines: While the original Czech material is historic, the most spectacular, vibrant pink specimens in recent years have come from the N’Chwaning Mines in the Kalahari Manganese Field of South Africa. I also have a deep respect for the classic material from the Trepča valley in Kosovo and the Franklin Mine in New Jersey, USA. For the vault, I prioritize the South African material for its intense pink saturation and the Czech specimens for their historical pedigree and classic crystal form.

Mineralogical Profile

Description: Kutnohorite is a calcium manganese magnesium iron carbonate that crystallizes in the trigonal system. It sits at a 3.5 to 4 on the Mohs scale, making it a soft and delicate mineral that should be handled with care and kept away from acids. It is characterized by its vitreous to pearly luster and its typical range of white, pale pink, and light brown colors.

One of its most identifying traits is its crystal habit; it often forms as rhombohedral crystals with curved faces, giving it that characteristic “saddle” look. It is often found in association with other manganese minerals like Rhodochrosite. Because it is a carbonate, it will effervesce (fizz) slightly in warm hydrochloric acid. It has a moderate refractive index ($n \approx 1.51$ to $1.72$), which provides a soft, glowing brilliance rather than a sharp fire. When I select pieces for the collection, I look for those with a high “lustre-sheen,” as this highlights the delicate, layered growth that is the hallmark of the species.

Chemical Formula: Ca(Mn²⁺,Mg,Fe²⁺)(CO₃)₂