Quite a rare find. This very attractive geometric design is Arabia Finland’s “Revontuli”, produced at Arabia from 1954 – 1963.
The form design is of course classic Kaj Franck, on his “TM” Shape, and the pattern design is by Raija Uosikkinen.
The TM shape was designed by Franck in 1948, inspired by a coffee service in made by the Imperial Porcelain Factory of St. Petersburg for Emperor Paul 1 of Russia.
When designing this form Franck did not include a recess in the saucer to hold the cup, which kept the form pure in appearance – and as a consequence the saucer can also be used as a small sweet/cake plate.
Raija designed 3 colour-ways for the series as far as I can find out – Blue, Red and a Yellow Ochre.