slabongrade

Slabongrade is a fictional mineral class used in geology-inspired fiction and educational exercises. It is described as a layered, tabular silicate mineral with a distinctive slab-like crystal habit and high structural rigidity. The name combines references to its slab-shaped crystals and the concept of graded, sheet-like layers within its structure.

Formation and occurrence in the fiction describe slabongrade as forming in high-pressure, low-fluid metamorphic environments, typically within subduction-zone rocks that recrystallize into stacked sheets. It is commonly associated with phyllosilicates such as micas and chlorites and is said to occur in shear zones and pegmatitic pockets, where layered crystals can develop.

Properties attributed to slabongrade include a Mohs hardness around 7 to 8, relatively high density, and a metallic to sub-metallic luster. The mineral is often depicted in shades of gray to silver and tends to cleave along flat, slab-like surfaces. In fictional variants, its composition is described as layered silicates with aluminum and magnesium, with trace elements influencing color and luster.

Uses and significance within the fictional setting emphasize its strength, heat resistance, and visual appeal. Slabongrade is imagined as a material for thick structural slabs, armor plates, or architectural panels in science-fiction environments, as well as a decorative or ceremonial gemstone in some narratives.

Etymology and classification notes state that the term slabongrade derives from the slab-like habit of its crystals and the concept of graded layers within the crystal structure. Slabongrade is not recognized in real-world mineral catalogs and remains a construct of fiction and educational demonstration. See also: slab-on-grade in real-world terminology.