Ilustandardite

Ilustandardite is a fictional mineral used in geoscience education and speculative writing to illustrate mineral identification and classification methods. It is not recognized by major mineralogical databases and has no verified natural occurrence outside teaching contexts.

Etymology: The name combines elements related to illustration and standard practice, with the customary mineral suffix -ite. In the classroom and in fiction, ilustandardite serves as a standard example rather than a real species.

Occurrence and formation: In common teaching scenarios, ilustandardite is described as forming in hydrothermal veins within basaltic host rocks of a fictional region called the Lumen Province. Formation is imagined under moderate temperatures and pressures, with available aluminum, silicon, sodium, calcium, and trace elements that stabilize a layered aluminosilicate framework.

Composition and structure: Ilustandardite is described as a layered aluminosilicate with a mixed sodium-calcium framework and minor magnesium and iron. A representative formula is given as (Na,Ca)2(Mg,Fe)5AlSi3O14(OH)2, with a monoclinic crystal system. Crystals are said to be pale blue to colorless and to have a vitreous luster.

Physical properties and identification: Hardness is stated around 5.5–6 on the Mohs scale, and density about 3.0–3.2 g/cm³. It is described as having cleavage parallel to basal planes and a refractive index near 1.58–1.60. In educational settings, X-ray diffraction and infrared spectroscopy yield characteristic patterns used to teach interpretation techniques.

Classification and uses: In real mineral taxonomy ilustandardite would be categorized among aluminosilicates, but as a teaching construct it is not part of official lists. It is used to demonstrate methods such as hardness testing, streak, cleavage, and diffraction interpretation in coursework and textbooks.