Short answers, pulled from the story.
Viking art, also known as Norse art, refers to the art of Scandinavian Norsemen and Viking settlements during the Viking Age of the 8th-11th centuries. It includes art made in Scandinavia and in Viking settlements in the British Isles, Iceland, and elsewhere. The tradition is organized into six overlapping stylistic phases, from the Oseberg Style through to the Urnes Style in the late 11th and early 12th centuries.
The original colors of most Viking artefacts have faded or vanished over the centuries due to deterioration in the ground. Pigment traces found on wood and ships reveal that Vikings frequently painted carved designs, shields, and wooden surfaces with natural pigments mixed with oils or fats. The objects surviving today are far less vibrant than they would have appeared when new.
Tortoise brooches are large, domed brooches that married Viking women used to fasten their overdresses near the shoulder, typically worn in matching pairs. Scholars call them tortoise brooches because of their domed shape. Women often suspended metal chains, strings of beads, or ornaments between or from the bottom of the brooches.
The Mammen Style is named after an iron axe recovered from a wealthy burial mound at Mammen in Jutland, Denmark. Dendrochronology dates the wood of the grave chamber to winter 970-971. The axe, richly decorated with inlaid silver designs, was probably a ceremonial weapon belonging to a man of princely status. Its key characteristics include pelleted tendril designs, a bird motif with a crest and lappet, and a spreading foliate pattern on the reverse face.
The English archaeologist David M. Wilson and his Danish colleague Ole Klindt-Jensen created the foundational chronological framework in their 1966 survey work Viking Art. The Norwegian archaeologist Haakon Shetelig produced the detailed early publication of the Oseberg ship-burial wood carvings in the early 20th century. The Norwegian art historian Signe Horn Fuglesang joined Wilson in subsequent decades, contributing her own important series of publications.
The Urnes Style was the last phase of Scandinavian animal art, dating to the second half of the 11th century and the early 12th century. It is named after the northern gate of the Urnes stave church in Norway. The style is characterized by slim, stylised animals interwoven into tight patterns with slender almond-shaped eyes and upwardly curled appendages. Most surviving examples are runestones in Uppland, Sweden, which is why some scholars call it the Runestone style instead.