diffusionglaucophane

Diffusionglaucophane is a rare silicate mineral belonging to the amphibole group. Its chemical formula is Na2Mg3Al2Si8O22(OH)2. It is a member of the glaucophane-riebeckite series, often found as an end-member or close to it. The mineral is characterized by its distinctive blue to violet color, though this can vary depending on the presence of trace elements. The "diffusion" in its name refers to the complex solid solution processes that lead to its formation and the variations in its composition.

This mineral typically forms under high-pressure, low-temperature metamorphic conditions, commonly found in blueschist facies rocks. These conditions are often associated with subduction zones where oceanic crust is forced beneath continental plates. Diffusionglaucophane can also occur in eclogites and some serpentinites. It is usually found in association with other high-pressure minerals such as jadeite, lawsonite, and omphacite.

Notable occurrences of diffusionglaucophane have been reported in various locations globally, including Japan, Italy, and the United States. Its rarity and specific formation conditions make it a mineral of interest to geologists studying metamorphic petrology and plate tectonics. The crystal structure of diffusionglaucophane is monoclinic, similar to other amphiboles.