dubhnite

Dubhnite is a rare mineral with the chemical formula Fe2+3Fe3+2(BO3)O2. It belongs to the ludwigite group of borate minerals and is characterized by its dark color and often prismatic crystal habit. The mineral is found in specific geological environments, typically associated with metamorphosed carbonate rocks and skarns that have undergone iron metasomatism.

The discovery and naming of dubhnite are attributed to American mineralogists in the late 20th century, recognizing its distinct crystallographic and chemical properties. Its formation requires the presence of iron, boron, and oxygen under elevated temperatures and pressures, often in the vicinity of igneous intrusions. The boron component is particularly notable, as boron-rich minerals are less common than silicates or oxides.

Dubhnite's physical properties include its hardness, typically around 5 on the Mohs scale, and a specific gravity in the range of 4.3-4.5. It exhibits a vitreous to submetallic luster and can be opaque to translucent. While not a widely known or economically significant mineral, dubhnite is of interest to mineralogists and geologists for its role in understanding boron geochemistry and the petrogenesis of specific metamorphic terrains. Its rarity makes well-formed specimens highly sought after by collectors.