gadoliniumia

Gadoliniumia is the name given to a hypothetical rare-earth mineral that would contain gadolinium in its crystal structure. The designation is used primarily in speculative mineralogy and in thought experiments about gadolinium-rich phases, and it has no verified natural occurrence in the scientific record.

The theoretical mineral would incorporate gadolinium in the +3 oxidation state, with its framework built from silicate or phosphate groups. In common speculative models, idealized formulas such as (Gd,REE)2SiO5 or (Gd,REE)PO4 are used to illustrate possible chemistries, with other rare-earth elements commonly substituting for gadolinium.

Crystal structure in these models is not fixed; possible systems include monoclinic or orthorhombic arrangements. Local coordination of gadolinium would likely involve eight to nine oxygen neighbors, depending on the specific anion pairing.

Occurrence and formation: In hypothetical contexts, gadoliniumia would be expected in granitic pegmatites or other rare-earth-rich rocks, and could form through late-stage crystallization or hydrothermal processes. It is often imagined as coexisting with known rare-earth minerals such as xenotime, monazite, and gadolinite.

Physical properties and potential uses: Predicted properties include a high density due to gadolinium, a vitreous luster, color ranging from pale to brown, and a Mohs hardness around five to six. As a gadolinium-bearing phase, its discovery could influence studies of rare-earth mineralogy, but it currently has no confirmed practical applications.

Status: Gadoliniumia remains a hypothetical construct without peer-reviewed confirmation; its discussion serves to illustrate the diversity of gadolinium-bearing mineral phases and the range of possible solid solutions in rare-earth systems.