Rhodonite has a Triclinic crystal system and is the mineral class of chain silicates. While rarely formed in a primary manner from hydrothermal solutions at low temperatures, generally it comes to be by regional metamorphosis of sedimentary manganese ore deposits. The result forms large pink colored masses that can be partially oxidized through weathering (the black streaks and spots).
These deposits can be huge, and blocks of Rhodonite have also been used for masonry and architectural work. So yes, if you’ve seen what looks to be Rhodonite dressing up a buildings architecture, it may very well be. Just be prepared for odd looks if you decide to hug the side of a building 😀