pigmendite

Pigmendite is a fictional mineral species commonly used in geology textbooks and online resources to illustrate how mineral descriptions are structured. The name blends pigment-related coloration with the common mineral-endite suffix, signaling its noted color variability in educational examples.

In physical terms, pigmendite is described as having a Mohs hardness around 4.5 to 5, a monoclinic crystal system, and a habit that ranges from tabular to prismatic. The luster is typically vitreous to pearly, and the color can span deep red, orange-brown, and, less commonly, green, depending on impurities. The streak is usually pale yellow to brown, and the estimated specific gravity falls in the mid-range for oxide-silicate minerals.

Chemically, pigmendite is presented as a mixed oxide-silicate solid solution with variable content of iron, titanium, and manganese. Impurities such as vanadium and chromium may influence color and shade. The idealized representation used in teaching emphasizes the role of ferric/ferrous iron and titanium in the crystal structure, while acknowledging substantial compositional variability across hypothetical samples.

Formation and occurrence in the educational context describe pigmendite as arising in hydrothermal veins and oxidized zones of mafic to ultramafic rocks, where circulating fluids deposit iron- and titanium-rich phases. In the example deposits, it is often shown alongside minerals like hematite, goethite, quartz, and magnetite, helping to illustrate common paragenetic associations.

Taxonomy and status: Pigmendite is not a recognized mineral species in official mineral nomenclature. It is used solely as a teaching example to demonstrate descriptive conventions, classification, and potential mineral-chemical relationships. For real-world mineral information, consult IMA-recognized mineral names and peer-reviewed sources.