Gradite

Gradite is a name that appears in geology education and in some works of fiction to denote a hypothetical mineral. It is not currently recognized as a real mineral by the International Mineralogical Association, and there is no universally agreed-upon chemical formula.

In most educational depictions, gradite is described as a silicate mineral with a layered or framework structure and variable cation content, often representing a solid solution between related end-members such as calcium, magnesium, and iron bearing phases.

Physical properties commonly assigned to gradite in teaching resources include: color pale to dark gray or green, transparency from translucent to opaque, luster vitreous, hardness around 5–6 on Mohs, and a specific gravity near 3.0. Habit is typically massive or prismatic; cleavage may be imperfect or found along pseudo-layering.

Formation and occurrence in these contexts are synthetic or hypothetical: gradite is used to illustrate crystal-structure concepts, zoning in metamorphic rocks, and routines for mineral identification. It may appear in classroom specimens, computer simulations, and fiction where a mid-grade silicate mineral is needed.

Etymology: the name gradite is commonly linked to gradient or gradual change, reflecting the imagined compositional zoning along geologic gradients.