By Kirsten Campbell BBC Scotland

An Edinburgh jeweller has finally decided to retire after cleaning the Scottish crown for more than 50 years.

Bill Jameson has been cleaning the royal crown for more than 50 years

Bill Jameson, 87, was first tasked with polishing the Honours of Scotland back in 1954.

But he has decided to call it a day after dusting down the crown for the last time ahead of this weekend's royal opening of the Scottish Parliament.

It is made of gold with 22 gems, 20 precious stones and 68 pearls - but it takes just a nail, a brush and some good, old-fashioned elbow grease to get the crown up to scratch.

"It's quite normal household ammonia and whitening and that really takes the grime off it first and puts a slight shine on it," said Mr Jameson, revealing his secret to achieving a sparkling crown.

"With the likes of these things, you can't beat hot water. It's the best cleaner there is really, water and soap."

It's just a crown to me Bill Jameson

Mr Jameson clearly remembers the day his firm won the contract to clean the Honours of Scotland more than half a century ago.

"It was the day King George died that we were up in the castle and were given the contract, but I had never seen the jewels, not even as a schoolboy."

Based in an Edinburgh jewellers, Mr Jameson was used to such riches.

"I worked for a Princes Street firm who are (now) defunct. We had a strong room full of stuff belonging to dukes and earls, so you were always used to cleaning good stuff."

The crown was the same one used at the coronation of Mary Queen of Scots. She was just nine months old at the time, but Mr Jameson is not phased by its historic significance.

"It's just a crown to me," he said. "It is the brick and mortar of my trade and I just get on with it."

And get on with it he has, every year for decades.

The crown is a very intricate piece. It has to be taken apart to be cleaned and the complicated bit is putting it all back together again in the right order.

The crown will make an appearance at the opening of parliament

Richard Welander, head of collections at the heritage agency Historic Scotland, said Mr Jameson's expertise had been vital to preserve the honours for future generations.

"Sir Walter Scott discovered them in 1818 having been locked away for many a long year and during the last war they were buried in David's Tower and they need to be carefully looked after.

"They've had a turbulent history and Bill has been looking after them for 50 of those 500 years and done a remarkable job."

But this is the last time Mr Jamieson will clean the Crown of Scotland. He will next see it on Saturday when it takes pride of place at the royal opening of the Scottish Parliament.