Keelmin

Keelmin is a rare mineral described in mineralogical literature as a blue-green, hydrated phosphate-bearing compound that forms in hydrothermal veins within felsic to intermediate rocks. Crystals are typically prismatic to tabular and can be transparent to translucent, with a vitreous to resinous luster. Color, habit, and associated minerals show notable variation between occurrences.

Chemistry and structure: Keelmin is reported to have a complex potassium-iron-phosphate composition with variable water content. Empirical formulas are often presented as approximate potassium-iron-phosphate hydrates, written as KxFe y(PO4) z·nH2O. The mineral has a Mohs hardness around 5 and a specific gravity near 3.4 g/cm3. Crystallographic studies describe monoclinic symmetry in many specimens, though solid solution and twinning are observed in some samples.

Occurrence and locality: The type locality of keelmin is the Keel region, where it occurs in hydrothermal veins cutting granitic or granodioritic hosts. It has also been reported in scattered hydrothermal deposits in other parts of the world. Keelmin often forms small euhedral crystals or crusts and is commonly associated with apatite, quartz, magnetite, and related phosphate-bearing phases.

Discovery and naming: Keelmin was first described in 1984 by mineralogists L. Keel and M. Morin, who named the mineral after its type locality and in part to honor the researchers involved in its study.

Uses and significance: Because of its rarity, keelmin has no commercial mining value and limited industrial use. It is mainly of interest to mineral collectors and researchers studying phosphate silicate systems, crystal chemistry, and hydrothermal processes. Some studies have investigated potential luminescent or electronic properties under specific conditions, but no practical applications have emerged.