asteeltaan

Asteeltaan is a hypothetical mineral used in geoscience pedagogy to illustrate mineral classification, nomenclature, and solid-solution concepts. It is not an officially recognized mineral by the International Mineralogical Association and has no confirmed natural occurrence.

The name is a constructed term that follows common mineral-naming conventions, typically combining elements of imagined composition with a standard mineral suffix.

In the teaching description, asteeltaan is described as a silicate mineral with a layered or framework structure. A representative formula is given as (A,B)Si4O10, with substitutions of Fe2+ and Mg2+ for Al3+ in octahedral sites. The hypothetical crystal system is monoclinic, with approximate cell dimensions provided for illustration. The mineral is depicted as dark gray to black, with a metallic to sub-metallic luster and a gray-black streak. Cleavage is described as imperfect or absent, and fracture as irregular.

In the fabricated geologic setting, asteeltaan is said to form in hydrothermal veins within basaltic rocks, often in association with oxide and sulfide minerals. The scenario places crystallization at moderate temperatures from silica-rich fluids.

As a didactic example, asteeltaan is used to discuss criteria for mineral naming, the role of type specimens, and how solid-solution leads to continuous compositional ranges. It is part of a teaching toolkit rather than a field-observed mineral.