wagnerite

Wagnerite is a rare mineral with the chemical formula Mg2PO4F. It belongs to the apatite group of minerals, specifically the fluorapatite subclass, due to the presence of fluorine in its structure. It typically crystallizes in the monoclinic crystal system, forming prismatic or stout crystals. Pure wagnerite is colorless, but impurities can cause it to appear yellowish, brownish, or even greenish. Its hardness on the Mohs scale is typically between 4 and 5, and it has a vitreous luster. The density of wagnerite ranges from 2.8 to 3.1 g/cm³.

Wagnerite is an uncommon mineral found in metamorphic rocks, particularly in high-grade metamorphic environments like granulites and skarns. It can also occur in some igneous rocks, such as pegmatites and alkaline intrusions. Notable occurrences include occurrences in Austria, Norway, and the United States. It is often found associated with other magnesium-rich minerals, phosphates, and fluorides. Due to its rarity and often small crystal size, wagnerite is not a commercially significant mineral. It is primarily of interest to mineralogists and geologists for its crystallographic and geological significance. The mineral was named in honor of Franz von Wagner, a German chemist and mineralogist.