Penberthy Croft Mine, is a disused mine and Site of Special Scientific Interest

Site of Special Scientific Interest

A Site of Special Scientific Interest is a conservation designation denoting a protected area in the United Kingdom. SSSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in Great Britain are based upon...

 (SSSI) in Cornwall

Cornwall

Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, UK

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. It is located to the north of the civil parish of St Hilary

St Hilary, Cornwall

St Hilary is a civil parish and village in west Cornwall, United Kingdom. It is situated approximately five miles east of Penzance and four miles south of Hayle.Chynoweth is an area immediately north of St Hilary....

, 5 miles (8 km) east of the town of Penzance

Penzance

Penzance is a town, civil parish, and port in Cornwall, England, in the United Kingdom. It is the most westerly major town in Cornwall and is approximately 75 miles west of Plymouth and 300 miles west-southwest of London...

.

The mine was designated a SSSI in 1993, is listed as of national importance in the Geological Conservation Review

Geological Conservation Review

The Geological Conservation Review is produced by the UK's Joint Nature Conservation Committee and is designed to identify those sites of national and international importance needed to show all the key scientific elements of the geological and geomorphological features of Britain...

 and is the world type locality for connellite

Connellite

Connellite is a very rare mineral species, a hydrous copper chloro-sulfate, Cu19[32|SO4|Cl4]·3H2O, crystallizing in the hexagonal system. It occurs as tufts of very delicate acicular crystals of a fine blue color, and is associated with other copper minerals of secondary origin, such as cuprite and...

 and bayldonite

Bayldonite

Bayldonite is a rare secondary mineral with the chemical formula PbCu322H2O. It was first discovered in Penberthy Croft Mine, Cornwall, England, UK. It is named after its discoverer, John Bayldon....

. It is noted as the most important site in Britain for secondary ore minerals of lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

, copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

, and arsenic

Arsenic

Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...

and has had 40 mineral species recorded at the site.