One of the prominent mines known for producing specimens in the West Cumbrian Iron Field (formerly Cumberland) was focused on extracting hematite, the primary ore mineral. Most mines in this ore field were active from the mid-19th to the early 20th centuries, although some, like the Florence-Beckermet-Ullcoats complex and Halle Moor Mine in the southern portion of the district, continued operations into the latter half of the 20th century.