Politicians want to ban it, foodies love it, and we all need a little to survive.

Wars have been fought over it, empires built on it, taxes levied on it and sacks of it handed out to soldiers as wages. Yet after centuries of commodification, the salt without which humans cannot live has been vilified and declared an enemy of the people.

A New York congressman is currently trying to have the use of salt banned in the restaurant kitchens of the Big Apple; if he is successful, the British nanny state, already bent on reducing our consumption by a third, might well try to follow suit. But expect riots if legislation outlaws the salt pot: in the foodie world, sodium chloride is re-acquiring the status it long enjoyed in the Himalayas, whose native pink salt was once reserved for royalty.

Today, £12.95 (as against 48p for a canister of Saxa) will buy you 250g of those same Tibetan crystals from Harrods, glistening in a clear glass jar like giant rocks of rose quartz, and requiring a granite pestle and mortar to be made ready for table. Or you can buy the pink stuff ready-milled from Fortnum's, who will also sell you – in a deliciously covert brown paper wrapper – a pinch of the green stuff ("celery salt, one of Charlemagne's favourites"), the grey stuff ("raw, unrefined salt from the French coast"), and even some branded black stuff, extracted from lava rocks lying on the seabeds of Hawaii.

"We have had an ever increasing demand for these not very easily found salts," says Fortnum's buyer of savoury groceries, Sam Rosen-Nash. "It comes partly from a return to cooking from scratch, partly from customers searching for a taste they have enjoyed on their travels, like fleur de sel in France or Murray River salt from Australia. We decided to incorporate these in an own-label range, which has just celebrated its second birthday – and wouldn't have if the products had stayed on the shelves. We also keep Indian black salt for our customers who know about its uses in Indian cuisine." Salt sales at Fortnum's, which eschews the industrial stuff altogether – "our cooking salt is Maldon's" – rose a whopping 56 per cent in the four years to 2009.

Supermarkets are also experiencing a rise, even though overall UK salt sales are static, according to Mintel. The salt buyer at Sainsbury's, Amisha Mody, reports that in the last year Sainsbury's has seen a 19 per cent rise, mainly driven by JS Coarse Sea Salt, which is up 37 per cent. She explains: "The rise of scratch cooking and a strong celebrity chef culture has encouraged customers to experiment, and products such as Maldon's and Cornish Sea Salt are experiencing rapid growth in the market."

Mody now has her eye on introducing coloured salts – "we know these are popular with foodies" – and there are plenty to go at, for those with deep pockets. Hawaii produces red, as well as black, salt coloured by volcanic clay. India produces a deep purple salt with a sulphurous quality particularly appropriate for seasoning eggs, and salt flecked with green seaweed is coming in from the Brittany shores.

However, nostalgia for seaside holidays seems to be the main driving force behind the 'gourmification' of Britain's condiment shelves. "Sea salt represents more than a fifth of the UK market and is growing at 8 per cent a year," says Ellie Bradshaw of Cornish Sea Salt, one of the new British star performers riding the crest of this slightly unexpected (in the face of government health initiatives to reduce salt consumption) culinary wave.

The company turned over a fairly astonishing £700,000 in its second year of trading (just completed), more than double the first year's sales and beyond the dreams of what was envisaged when Ellie and her partner, Tony Fraser, invested £5,000 in producing just 5 kilos of Cornish Sea Salt to bring to London's International Food Exhibition in 2003: "We could have sold literally tons there and then if we had had it; people were really excited about the product," she says.

Cornish Sea Salt, which plays on the county's Iron Age salt-making heritage, has been endorsed by the likes of Hugh Fearnley- Whittingstall, Richard Corrigan and Rick Stein, and courted by firms such as Thorntons, who put its product into their salted caramels. They are currently developing a Breton-like butter which will be crunchy with salt crystals, and will next month launch a range of flavoured salts infused with roasted garlic, celery and caramelised onion.

There is much innovation going on too at Halen Mô*of Anglesey, whose vanilla salt has become a staple in the kitchens of seafood cooks – it's a classic match for lobster and scallops – as well as an ingredient in posh chocolatier Marc Demarquette's best-selling bar.

Heston Blumenthal, Gordon Ramsay and El Bulli supremo Ferran Adria have harnessed it for recipes – "our salt is particular in that it doesn't melt on hot food, so it will sit on top of a steak to lend a zesty crunch," explains founder Alison Lea-Wilson – and the smoked variety is a key ingredient in Barack Obama's favourite caramel milk chocolates from Fran's of Seattle.

With organic celery and spices making their way into yet more variants, Halen Mô*have come a long way since starting their company as an offshoot of their aquarium business 11 years ago. "That was very seasonal, and we were looking for something to provide year-round work for our employees," explains Lea-Wilson, whose adventures in salt began with her husband David "in a saucepan on the Aga in our family kitchen. We knew the water was pure, because we had been keeping sea horses in it, which are very exacting creatures. But we never envisaged that the salt would become so successful we would have to sell the aquarium!"

Originally harvested to supply their local butcher in Menai Bridge, Halen Mô*now distributes in 22 countries and 100 delicatessens, as well as to many of the same gourmet food stores and supermarkets that also stock Cornish Sea Salt. None of which fazes Clive Osborne, whose Maldon brand had a monopoly on British sea salt production for more than 100 years. "Salt- making in East Anglia goes back to Roman times, and 45 salt pans were listed in the Domesday Book," he explains. "We have the least rainfall in the UK here, and the saltiest river in the country in the Blackwater."

Maldon, which has been cited as the salt of choice by Jamie Oliver, Delia Smith and many other British cooks, is even more famous abroad: "More than 60 per cent of our production is exported – to Spain, France, Italy, Scandinavia and the Far East," says Osborne. "Our salt is made in the traditional way, and we are still selling the same product made when the company was founded in 1882."

In spite of this, Maldon led the move into flavoured salts, which has breathed new life into a staple seasoning with its oak-smoked varietal, particularly popular in Scandinavia and the US.

In New York, the very city whose congressman is trying to impose a salt ban in professional kitchens, some chefs are putting up to six different kinds out to tempt discerning diners: "There are several restaurants in the US pairing various salts with specific foods," says Stefan Czapalay, a chef and importer of salt from around the world.

"Taste is impacted by many things – the texture, the colour – even the shape of the crystals." He recommends trying a raw tomato test: "Sprinkle one half of a cherry tomato with Cornish salt and the other with sel gris or Himalayan. The latter will have an almost meaty taste, while the one sprinkled with Cornish salt will yield a far more tomatoey taste. It crunches, but dissolves more quickly, creating more saliva and carrying more flavour to the palate."

Salt pairing is a craze now practised not only in America but in countries as diverse as Dubai and Sicily: "Restaurants are even employing selmeliers – salt experts – as well as the sommeliers who consult on the wine list," says Lea- Wilson. She does not think this is at all at odds with the effort to get us to consume less salt, taking the wine analogy one step further. "If you adored wine, but were advised that you ought to drink less of it, you'd buy the best bottle you could afford, and absolutely savour every sip."

Perhaps the last word should go to Mark Bitterman, who preaches the virtues of gourmet salt from his home in Portland, Oregon. Bitterman is the self-styled president of the Selmelier's Association, and believes that "Gourmet finishing salts are the crystals through which our world can be seen in all its variegated and changing beauty."

No one gazing upon a rainbow of pink, green, gold, grey, black, purple and gleaming white sea crystals on their kitchen table would disagree with that, or with his reminder of the contrast between noisy industrial salt mines and the tranquility of sea-water harvesting. This aesthetic may well be the prime mover behind the rise in sales of sea salt. "Salt from industrial mines finds its way to our tables only as a refined by-product of a far vaster industrial need for salt," Bitterman observes. "Salt from the sea makes you want to travel, talk, learn, cook, and eat."

Magic crystals: The secrets of salt

Most salt sold in Britain is mined in Cheshire, but China and the US are the world's largest producers of table salt.

Commercial table salt is extracted from underground deposits, then stripped of all its minerals and reduced to pure sodium chloride. Chemicals are then added to make it free-flowing.

Rock salt from the Himalayas is also mined, but is left intact with the 85 minerals it contains. The existence of this salt source, laid down 250m years ago on what was then a seabed, was discovered by Alexander the Great.

Sea salt is produced from seawater, which is evaporated, filtered and rinsed clean. It contains many trace minerals, including magnesium, calcium, zinc and even tiny proportions of silver, copper and gold. Some sea-salts, like those from the beaches of Bali, have a pyramid-like structure; others, like Halen Môn, are large, flat flakes.

Dozens of countries exploit their sea salt, sometimes so intensively as to be detrimental to the marine ecology, as is reported to have happened in Venezuela and Mexico.

Gourmet salt is now finding its way into 21st-century cocktails and caramels. Chocolatiers love it, and some people even like to sprinkle a few flakes of sea salt on top of their hot chocolate drinks.