Yttriaite-(Y)
Yttriaite-(Y) is a rare earth silicate mineral with the chemical formula Y2Si2O7. It is a dimorph of thalenite-(Y), meaning that it has the same chemical composition but a different crystal structure. Yttriaite-(Y) crystallizes in the monoclinic crystal system, whereas thalenite-(Y) crystallizes in the orthorhombic system.
The mineral is typically found in metamict (radiation-damaged) form, often appearing black or dark brown in color. In some cases, metamictization may alter its properties considerably. Its name derives from its yttrium (Y) content, a major element in its composition. The "(Y)" suffix in the name is used to indicate the dominance of yttrium within the rare earth element site.
Yttriaite-(Y) is typically associated with granitic pegmatites and other rare-element bearing igneous rocks. It can also occur in metamorphic environments. Associated minerals often include other rare earth minerals, quartz, feldspar, and mica.
Due to its rarity and metamict state, the physical properties of Yttriaite-(Y) are not always easily determined. However, it is generally known to be relatively hard, brittle, and possesses a vitreous to greasy luster. Its density can vary depending on the extent of metamictization and hydration.
Identification typically relies on X-ray diffraction analysis, which can determine its crystal structure and confirm its identity. Chemical analysis is also used to verify the composition and relative abundance of yttrium and other rare earth elements.
Yttriaite-(Y) has no significant industrial uses. Its importance lies primarily in its scientific value as a representative of rare earth mineralogy and its contribution to understanding the geological processes in which it forms.