A "lost" vein of rare Blue John stone has been rediscovered in a Peak District cavern after a 68-year search.
In 1945, miner John Royse reported finding an "amazing deposit" in Treak Cliff Cavern, Castleton.
However, he was taken ill and died before he was able to share the exact location with the Harrison family, who had taken over the running of the mine.
Blue John is made from fluorspar which has reacted with other chemicals to give it its unique banded streaks.
It formed millions of years ago and is used to make ornaments and jewellery. Only a small amount of the semi-precious mineral is allowed to be mined each year.
'Old miner's tale'
The deposit of the stone was uncovered deep down beneath an old piece of carpet.
Peter Harrison, who was 19 at the time of Mr Royse's discovery, said: "I was just a young lad when my family took over the running of the cavern.
"The old miner, John Royse, was not in the best of health and was retiring.
"He told me of this fantastic deposit of Blue John he had found and asked me to help him get it out.
"We planned to return to the cavern the next day but sadly John Royse was taken ill and died.
"Over the years I have spent countless hours searching for that deposit."
The stone was discovered by Mr Harrison's grandson, John Turner.
The 21-year-old said: "It was while we were stood talking at the bottom of the ladder that leads to the upper galleries that I noticed something unusual on the floor.
"After an hour of digging through muddy deposits, I was amazed to come across an old piece of carpet supported by some wooden batons.
"I couldn't believe my eyes when we pulled away the old carpet and there was this most amazing deposit of Blue John stone."
Mr Harrison's daughter, Vicky, said: "I grew up with stories of John Royse's lost deposit.
"To be honest, I thought it might have been a bit of an old miner's tale.
"It is a sizeable deposit and we conservatively estimate that there is enough Blue John stone in this deposit to keep us busy for the next decade at least."