Hand sized, bronze and unspectacular (especially compared to others from the same period) this brooch is typical of the time we now call the Migration period.
It is cross shaped, hence the name, with stubby little arms at the top that end in thick angular lumps. At the bottom we can spot an animal head. It has a long snout, protruding eyes and sleeked down or maybe braided hair.

We have more than 600 similar pins in Norway alone, and about a thousand in Scandinavia in total. This one was discovered in a grave mound in 1890. It came into the museum from an excavation by Nicolay Nicolaysen, one of the very first Norwegian archaeologists.

• Haakon Shetelig 1906: The Cruciform Brooches of Norway. Bergen Museums Aarbog
• https://www.unimus.no/portal/#/things/aaddc283-4d81-4c1d-afb3-d1d64196f1b5
• De levende og de døde – 400-600 e.Kr. | lex.dk – Danmarks Oldtid Link
• Fibula (spenne) – Wikipedia Link