A woman who lost a sentimental ring given to her by her teenage sweetheart 46 years ago has wept tears of joy after it was found in a chance discovery.

Phillip O'Brien presented his girlfriend Glenda - now his wife - with a friendship ring in 1971 engraved with the words 'To Glenda love Phillip', along with the date.

Three years later, Glenda was washing the car at the Gold Coast block of units where they lived when the ring slipped off her finger unnoticed and onto the muddy driveway, never to be see again - until now.

'I lost this ring when l was washing our HD Holden in the dirt driveway at our flat on the corner of Hilda street and Gold Coast Highway Mermaid Beach in 1974,' Ms O'Brien posted on Facebook.

'We used to drive past and l would always think of that ring as l knew l must have stood on it and sunk is the dirt as l searched everywhere around and couldn't find it.'

The heartwarming moment an emotional Glenda O'Brien was reunited with her missing ring as her lifelong partner Phillip watches on

The ring lay undiscovered until local resident and metal detecting enthusiast Jason Kemp was running his detector across a now vacant lot recently when he got a beep.

Digging down about 20 centimetres, he discovered the gold ring.

While normally he keeps his discoveries, on this occasion he realised the possible sentimental value because of the inscription, so he posted pictures and information on the Gold Coast Community Facebook Page in the hope the rightful owner would come forward.

'It was quite deep so it's been in the ground some time,' he posted.

'Hopefully this couple is still together and we can help them celebrate the upcoming 50 years with this ring.'

The ring (pictured) cost $38 in 1971 and has spent the last 46 years buried in the ground

Mrs O'Brien was in touch two days later after being alerted to the Facebook post by an old friend she hadn't heard from in years.

'I didn't tell anyone where I exactly found it,' Mr Kemp told the ABC.

'I just said 'on the the Gold Coast,' and she came to me with her story of where she lost it, and 'I was like yep, it was 100 per cent yours.''

Mr Kemp shared later on Facebook shared the heartwarming message he received from Mrs O'Brien after they'd realised it was hers.

Mr Kemp handed the ring over on Sunday to a delighted Mrs O'Brien.

'So what are the chances? I met my husband in 1969 he bought me this friendship ring in 1971 we married in 1972 l lost this ring in 1974 and was devastated as it was the first thing Phillip bought me,' an ecstatic Ms O'Brien posted on Facebook on the weekend.

'When l seen the picture of my ring l actually cried.

Glenda and Phil OBrien, pictured in 2016 (right) and in the early 70s (right) will celebrate their 48th wedding anniversary this year and have been together for half a century

Mrs O'Brien said the sentimental jewellery was more precious than her wedding and engagement rings.

'Because it meant so much back then and time makes you forget things, when I put it back on it brings memories of when he gave it to me,' Mrs O'Brien told the ABC.

'We knew that we would end up together for the rest of our lives, and here we are — the ring has come back to us.'

The precious ring, which cost $38 in 1971 and took Mr O'Brien about two weeks to pay off will be passed onto their granddaughter.