A 1968 review by the Society for Medieval Archaeology of the UK proposed that it was a woollen cloth known for a broken diamond texture that was produced by early looms.
[1] As one of three kinds of cloth named in Magna Carta and in a variety of other medieval sources, it is believed to have been a major article of commerce in the 12th and 13th centuries.
The cloth could be dyed green, 'peacock', dark brown, or in grain, and was available in coarse, good, or fine qualities, selling from 5.5d.
[1] The texture of the cloth is believed to have superficially resembled a hauberk (chain mail) due to the pattern of horizontal rows, known as a 'broken diamond' or 'broken lozenge' twill, which has been excavated from peat bogs dating back to the 4th century AD.
In Iceland, Norway, and Sweden such cloth is referred to as hringofann, meaning "hauberk", a term persisting to the present day.