The marble fragment comes from the Erechtheion temple, built around 420 BC and known for its ornamental decoration and pillars in the form of statues of women known as Caryatids, the Museum of Mediterranean and Near Eastern Antiquities said.
Birgit Wiger-Angner, a retired gym teacher, turned the piece over to the museum after reading an article about Greece’s desire to recover friezes from the main temple of the Parthenon, which were taken by Britain’s Lord Elgin in the 19th century and which London refuses to return.
Wiger-Angner inherited the piece – measuring 20 centimeters (7.8 inches) wide and eight centimeters (3.1 inches) high – from her father, whose brother Henning Lund acquired it from the Acropolis around 1895-1896 and took it to Sweden.
Until February 2005, the frieze served as a decoration in Wiger-Angner’s home.
Wiger-Angner is due to hand over the piece to Greek Culture Minister Georgios Voulgarakis at a ceremony to be held at the Acropolis on Friday, the museum said.
Suzanne Unge-Sörling, assistant head of the museum in Stockholm, said it was of great historical interest.
“Today the Erechtheion temple is a long way from being complete… the frieze is a piece of a puzzle… and the small number of similar pieces that have emerged… are mostly held by museums, for example the Metropolitan in New York,” Unge-Sörling told AFP.
The fact the frieze was not left in the open has helped preserve the piece from the effects of pollution.
Paint that once adorned the temple has disappeared due to the twin ravages of time and pollution, whereas some traces of paint remain on the piece to be returned on Friday, Unge-Sörling added.
The museum displayed the frieze since Wiger-Angner turned it over to the institution in February 2005.
After its return to Greece the piece will feature in a new Acropolis museum currently under construction in Athens.