frouxas

Frouxas are described in speculative geology and some science-fiction contexts as a class of porous, fluffy nodules that form within volcanic ash beds and related diagenetic sequences. They are typically composed of hydrated aluminosilicates and other silicate minerals, with a delicate, reticulate texture that gives them a light feel when handled.

Name and origin: The term frouxa is attributed in fictional literature to field researchers who credited the late explorer Dr. Amina Froux with first documenting the morphology in 2148 in the Froux Basin. The plural form frouxas is used for individual nodules within a sampled population.

Physical properties: Frouxas commonly measure 1 to 5 centimeters in diameter, with occasional specimens larger. They exhibit colors ranging from pale beige to cream, and sometimes pale green. The surface is porous and soft, with a Mohs hardness around 2 to 3. Their bulk density is relatively low due to the interconnected pore network.

Formation and occurrence: Formation involves rapid hydration and alteration of volcanic glass and feldspathic minerals, typically in ash layers undergoing early diagenesis. In the fictional record, hydrothermal fluids and episodic gas release contribute to the development of a spongy, interconnected pore structure that defines the nodules.

Research and applications: In narrative settings, frouxas are studied as indicators of ancient hydrology and gas migration in volcanic systems. Their porosity has led to speculation about potential lightweight aggregate properties and adsorptive behavior, though they remain a conceptual construct within real-world science.