Spinelluokan

Spinelluokan is a proposed mineral name used in speculative mineralogy to describe a spinel-like oxide that would occupy an end-member position in the AB2O4 family. The term derives from spinel and a suffix used for newly described varieties. It is not an IMA-approved mineral name and remains a topic of theoretical discussion and experimental synthesis.

Structure and composition: Spinelluokan would crystallize in the cubic system, typical of spinels, with a partial cation ordering between tetrahedral A sites and octahedral B sites. The idealized end-member formula is (Mg,Fe2+)Al2O4, with possible substitutions by Cr3+ and Fe3+. These substitutions influence color, refractive index, and stability under high pressure.

Occurrence and formation: In theory, spinelluokan would form under high-temperature, high-pressure conditions in ultramafic rocks or during metamorphic processes that stabilize spinel phases. Reported natural specimens are not established; synthetic samples have been produced in laboratory conditions to explore phase relations within the spinel group.

Properties and potential applications: Predicted physical properties resemble those of common spinel, including Mohs hardness around 7.5–8 and a vitreous luster. The material could have gemstone potential if color and clarity can be controlled; more likely it would be studied for high-temperature ceramics and refractory materials.

Etymology and status: The name spinelluokan reflects its proposed relation to spinel. As of this writing, it remains an informal designation used in theoretical discussions and is not widely recognized in mineralogical databases.