Hundreds work in the gloom, enduring poor air quality
By Martin Patience
BBC News, Panjshir valley, Afghanistan
It all felt a bit ominous. With a rucksack packed with five litres of water I was struggling my way up the Hindu Kush mountain range, thousands of feet above sea-level.
Behind me was a man carrying a yellow sack - a yellow sack packed with explosives, that is.
And then on the way up the narrow path, I spotted three or four green Islamic flags marking a gravestone.
What happened there, I wondered. Well, it seemed that someone had been taking a rest - his last as it turned out - when he was struck by a rock fall.
But the reason for all the pain and high-altitude panting was simple: we were heading to the emerald mines.
The journey had started three hours earlier in the village of Kheng.
It was the kind of place that seemed strange even by Afghan standards.
Most of the shops were a neat row of shipping containers. And almost everyone seemed to have slips of white paper they would unwrap for you to reveal emeralds.
The stones weren't dazzling; in fact, they looked like dull shards of glass. They only shine after they are cut and polished.
The mountains here are like Swiss cheese, burrowed with mine shafts
But for the few hundred villagers of Kheng - it meant money - and lots of it.
The source of that wealth, the mines, was above the snowline.
At first, there wasn't a lot to look at - apart from flying stones that hurtled their way down the slopes.
But once you had caught your breath, and looked closer, you saw it for what it was: a frontier post perched high on a mountain.
Parts of the mountain were like Swiss cheese - burrowed with mineshafts.
About 300 men worked up here - living in caves, or, if they were lucky, in mud houses. Some stayed up here for weeks on end.
They worked in teams - miners, diggers, explosive experts, cooks, and suppliers. They shared the profits of any emeralds that were found.
You could buy in as part of a syndicate - and provide, say, a donkey-load of rice which would guarantee you a share.
But you needed luck in this place if you wanted to get rich.
Mohammed, the manager of one of the mines, told me that he had seen people work for 10 years and find absolutely nothing.
Some miners strike lucky quickly - others not at all
And then he had seen people mining for two weeks walking away with a haul of the precious stones.
More worryingly, Mohammed told me that 30 miners had been killed or seriously injured by explosions or fumes in the mineshafts in the past 10 years.
Unsurprisingly, there wasn't a great deal of science or safety considerations when it came to mining here.
At the entrance to one of the operational mines, four miners, looking like sooty moles, appeared to be enjoying the daylight after hours of darkness.
Armed only with a torch, I walked into their gloom. I was forced to scramble up steep inclines. The air quality got worse and worse the further I went. It felt like walking into a smoker's lung.
After walking for a few minutes, the noise of a drill started echoing through the rough-cut tunnel.
There were two young men. They packed the drilled hole with explosives scooped out of a plastic bag. And then fitted it with a charge.
I didn't fancy hanging about to see the explosion going off.
So I made the hastiest turn of my life and half-stumbled down the mineshaft, trying to mind my head and trying not to drop my torch.
I then shouted at Mahfouz - the BBC's ever-patient producer - that we needed to stick together - it's very dangerous! We can't be messing about at times like this.
Accidents have killed or wounded 30 miners in the past decade
A few seconds later he arrived - face puffing - and calmly said: "Martin you're going the wrong way."
When the explosions went off - I wasn't actually out of the mine. Instead, I was at a so-called "safe" distance.
I didn't really hear very much - it was so loud - I just felt a rush of dust passing over my face and then my ears popped.
After the dust and my nerves started to settle, I asked one of the miners how he felt when he saw an emerald. He told me that he forgot the hardship and fatigue of a year's work.
He then motioned to go back up the shaft to see whether the explosion had hit a seam of emeralds.
But I decided not to take him up on the offer.
To be perfectly honest, I'd had enough for one day - emeralds or no emeralds.