Jewels of the heart that dance right in . . . wondrous designs by Russian artist Viktor Alexandrovich Hartmann 1834-1873). Perished at a tragically young age so this is (almost) all there is and there isn’t any more.
All are in the public domain due to age. Many can be found in various places around the internet but I found them here: https://tatasoz.livejournal.com/2657941.html. Where you can also see some of his lovely building images.