Just to join in the debate as nearly the newest member of the site.
Mineral rights can be a diffcult area. Anecdotally there was a field in Cornwall of a few acres whose mineral rights were 'owned' or at least claimed by 4 people. Their respective shares of the field added up to something like (from memory) 187/133 of the area!! One for the lawyers - the mining company who were trying to gain access walked away!!
http://www.bgs.ac.uk/mineralsuk/free_downloads/home.html#GUIDE I can offer the following
The rights to non-fuel minerals in Great Britain, with the exception of gold and silver, are mainly in private ownership although a significant proportion is owned by the Crown and by Government departments and agencies. Uranium and other prescribed minerals relating to the production of atomic energy belong to the mineral rights owner, but may be compulsorily purchased by the Secretary of State for Trade and Industry with compensation under powers granted in the Atomic Energy Act 1946. Although mineral rights are generally held by the surface landowner, they may have been retained by a previous landowner when the surface freehold was sold, particularly in areas with a long history of mining such as south-west England. There is no national register of mineral rights, but the Land Registry may have details of surface ownership and current ownership of mineral rights. The registers are open for public inspection.
The right to exploit minerals in the foreshore (beach) and on the sea bed within the limits of national jurisdiction is vested in the Crown under the Continental Shelf Act 1964 and, apart from coal, oil and natural gas, these resources are managed by the Crown Estate Commissioners. The only exceptions are the counties of Cornwall and Lancaster, where the foreshore is owned by the respective Duchies, and where grants of the foreshore have been made by the Crown to other parties.
The mineral rights to the noble metals, gold and silver, in most of Britain are owned by the Crown, and a licence for the exploration and development of these metals must be obtained from the Crown Estate Commissioners through the Crown Mineral Agent. The areas currently under licence are shown on a map (updated annually) in the United Kingdom Minerals Yearbook.
The rights to gold and silver in the former county of Sutherland in northern Scotland are held by the Duchy of Sutherland.
In the Isle of Man title to all minerals, including gold and silver, is vested in the Manx Department of Industry through the Minerals Act 1986. The Department issues exploration and development licences.
All minerals in Northern Ireland, except gold and silver (already owned by the Crown) and 'common' substances, including sand and gravel and aggregates, are vested in the Department of Economic Development (now the Department of Enterprise, Trade and Investment (DETI)) by the Mineral Development Act (Northern Ireland) 1969. The Department grants prospecting and mining licences.
Mining companies do carry out exploration in Britain and do negotiate mineral rights successfully - but it can be a bit of a job.
Tim