Monteregianite-(Y)

A fine microcrystalline example of Monteregianite-(Y) from the classic Mont Saint-Hilaire alkaline complex, the type and only significant locality for this rare yttrium-bearing phosphate–silicate species. This specimen hosts a few minute but well-defined crystals exhibiting the subtle brownish to pale yellow hues typical of the mineral. They are accompanied by associated albite, calcite, and quartz. Monteregianite-(Y) is known almost exclusively from Mont Saint-Hilaire, where it forms as a late-stage mineral in highly evolved pegmatitic and hydrothermal assemblages. Its occurrence is typically microscopic, and well-exposed crystals, even at micro size, are considered highly desirable by collectors specializing in rare-earth minerals or the unique mineralogy of the Monteregian Hills. Collected by Peter Tarassoff in 1999, this specimen is an excellent representative micro from the type locality, ideal for anyone seeking species-level completeness in a Mont Saint-Hilaire suite.