Mining for lead, copper and iron ore have been an important part of Cumbria's economy since the days of Elizabeth the First and copper is believed to have been worked at Coniston since Roman times.
After the Germans established a mining industry of some significance, centred around Keswick, in the 16th century, mining went through typical boom and bust periods until the 19th century when it enjoyed an era of exceptional economic activity. However it was not until the second part of this century that collectors recognised the area for its exceptional mineral specimens after so long being overshadowed by the well established Cornish specimen trade. The most famous collector who helped to make 'Cumberland' specimens desirable to the fashionable elite was Byrce Wright, a native of Caldbeck village, whose labels are much sought after today.
In recent years, Cumbria has suffered the same economic decline in metalliferous mining as other traditional mining areas of the British Isles, through exhaustion of the orebodies and/or economic factors. There are working quarries in Cumbria still, but compared to those in neighbouring Weardale, contain little of mineralogical interest,
The modern administrative county of Cumbria covers the old counties of Cumberland, Westmoreland and the Furness district of Lancashire, locations commonly seen on many old mineral labels. The area has produced some of the most outstanding specimens found in the British Isles and for some species perhaps the best yet found, many museums around the world having superb examples from here, particularly, barite, calcite, hematite, pyromorphite, plumbogummite, campylite (var. of mimetite), linarite, caledonite, fluorite and examples of many rarer species. Nearly all these specimens have come from 4 mining fields; West Cumbria, the Caldbeck Fells, Keswick and in the east, the Pennine escarpment. Surprisingly, given their occurrence in a relatively small geographically area, the mineralogy and species are very different, a result of the complex local geology and differing degrees of oxidisation of the orebodies.
Mining has taken place in other parts of the county, most notably around Coniston (copper), the Eden valley (gypsum) and Furness for iron but their mineralogical legacy is of lesser interest. Hodbarrow and Stank mine in Furness are perhaps the only exceptions to this with occasional specimens of excellent calcite and kidney ore to match those from West Cumbria.

The area has a number of museums worth visiting:-
Threlkeld Mining Museum
This has now moved to Keswick. it is developing into an excellent centre to study the history of mining and quarrying in the area, with artifacts, old quarry equipment, maps and minerals. It has recently acquired the W.T. Shaw mineral collection. Good selection of related books (new & second-hand) and minerals for sale.
Florence Mining Museum
Unfortunately I believe this museum has now closed following BNFL decision to cease pumping at the mine (2007).

Two public museums have mineral displays:-
Keswick Museum, Fitz Park, Station Road
Has a permanent display including excellent specimens from the Caldbeck Fells, West Cumberland and Greenside mine.
Tullie House Museum, Castle Street, Carlisle
The Millennium gallery has currently a mineral display including a fabulous blue fluorite from Ullcoats mine.

Note:-Always ask permission before visiting any mine or quarry, and never enter underground workings - they are extremely dangerous.