There is a lump of coal on the editor’s desk in the Guardian.

It is a beautiful and wondrous thing; it glistens and shines as bright as any gemstone in some up-market jeweller’s window.

It came from the ground less than two miles from where these words were written.

It is the stuff on which the communities of this valley – this part of Wales – were built.

Amman Valley anthracite is the finest coal on earth – and lots of it remains just below the surface.

It does not then seem quite as crazy as it sounds when Labour leadership hopeful Jeremy Corbyn talks of re-opening the Welsh mines.

No one in their right mind would want a return to the days when every son of this valley was doomed to lung disease thanks to a life underground - nor would we wish to for a return to a time when dozens of communities relied solely on a single industry for their survival.

Whether coal mining would ever become viable – or acceptable – here again it must also be remembered that people are flocking to Carmarthenshire because of its beauty, and whatever Mr Corbyn’s thoughts on a return to heavy industry, the reality of almost £350million a year coming into the county through tourism should never be underestimated.

Carmarthenshire is becoming a tourism hotspot – and long may it continue – but like mining in years gone by, we cannot put all our eggs into a single industry and hope it will sustain us forever more.

It seems absurd to think that in this day and age we cannot make the most of this most precious and perfect natural resource beneath our feet in a way that would allow us to maintain the environment while also providing work – and wealth – for our people.