This sculpture is a depiction of an angel grieving over an unknown urn, guiding the departed to heaven. Unfortunately we don't have any information about the artist, but clearly they must have been into the Neo-Classical style of the 19th century. The wings of the angel is most impressive and majestic, which is what makes this sculpture so beautiful. 

The State Museum of City Sculptures was founded in 1932 dedicated to the study, restoration and protection of city sculptures and gravestones and the museum is responsible for the upkeep of many of St Petersburg's most famous sculptures.  The museum has several branches around St Petersburg, but the main ones are concentrated within the former territory of the Aleksandro-Nevsky Lavra which was granted to the museum upon its founding.

The Aleksandro-Nevsky Lavra's Tikhvinskoe Cemetery was established in 1823 and named after the Our Lady of Tikhvin Church which was built here between 1869 and 1873.  In 1931 the church was closed and in 1932 the cemetery became a branch of the State Museum of City Sculptures, known as the Necropolis of Masters of Culture.  The branch is so named as many leading figures of Russian culture have been laid to rest here including: writers Fyodor Dostoevsky,  Nikolai Karamzin and Ivan Krylov; composers Aleksandr Borodin, Mikhail Glinka, Modest Musorgsky, Nikolai Rimsky-Korsakov and Pyotr Tchaikovsky; and artists Boris Kustodiev, Ivan Kramskoy and Ivan Shishkin, among many more famous names.