It's often said that personal style is more important than fashion fads and with the current emphasis being on the circular economy when it comes to clothing, there is a similar move towards pre-loved jewellery.

Thanks to social media trends, increasing numbers of diamond lovers are seeking more authentic and less costly jewellery from auction rooms.

As the cost of living escalates, people are increasingly value-conscious and seeking alternatives to an expensive, new diamond to celebrate engagements, as canny consumers realise that the depreciation rate on new diamond rings is extremely high.

The resale value of a ring can drop by two-thirds of the original price by the time you leave the shop so the appeal of buying a preloved ring for a lower price is obvious.

Dr Rachel Healy, Head of Jewellery at the Adam's of Blackrock, has seen the rise in popularity of pre-loved, vintage, and antique jewellery driving younger customers through the auction house doors.

Adams of Blackrock has now re-located to 17 Kildare Street, Dublin with a specific focus on jewellery. There they will hold monthly online auctions with viewings, where bidders can view lots in advance.

Now under the ownership of Northern Irish auction house, Ross's Auctioneers and Valuers of Belfast, Adam's of Blackrock is the first Irish auction house offering dual currency bidding (in Euro and Sterling) to clients across Ireland, Europe and Britain.

They have just launched a two-week auction of 420 lots, with Rachel revealing the gems and precious stones on offer.

She appreciates that buying a piece of jewellery is an intimidating experience - assessing the relative merits of diamonds, rubies, and sapphires, evaluating hallmarks and understanding terms like cut, clarity and carats can be hard for the untrained eye.

But we've been getting a lot more younger people coming to buy their engagement rings, wedding bands. I suppose it's the accessibility of being able to view and buy online as opposed to getting posted out a catalogue,' she says.

Diamonds remain a favourite Rachel says, but buyers are increasingly looking at different coloured diamonds not just traditional white stones.

'Diamonds come in every colour but they're obviously quite rare to get in different colours, but the fancy yellow diamonds have definitely become more popular,' she explains. 'And we do have a fancy yellow diamond cluster ring in this auction (Lot 686, estimate €2,500 to €3,500).'

'Some people like to think of the whole lab-grown diamonds as sustainable, but it's actually not what people think. Buying at auction, is sustainable. It's not even just second-hand; it could be that multiple people have owned a piece previously,' Rachel says.

Then there is the appeal of investing in a piece that is unique and original. 'Antique pieces are just so one-off as opposed to factory-made settings. The antique Art Deco, Georgian, Victorian, Edwardian pieces they're so intricate and they're very unique statement pieces,' Rachel says.

Of course, big brand names of any era are very desirable too.

'Tiffany is still very popular,' says Rachel. 'Brands do very well at auction because obviously they're way more affordable. Van Cleef, Cartier Rolex obviously is a big one. Rolexes always sell at auction and then you'll have specific designers so sometimes we'll get a once-off piece. If someone knows the designer, then they'll go for it.'

'People are always buying Rolex watches as an investment Rolex and diamonds are a sure winner,' she says. 'Obviously gold as well, as long as you're buying it at the right time.'

The diamond market can be tricky, though. 'People don't know what way it's going because of the synthetic diamonds but I don't see the synthetic diamonds lasting.

'They're not millions of years old like a natural diamond. So, it's not the same to me. Would you wear a synthetic ruby or would you rather a natural one? Would you rather have a fake Chanel bag or a real one?' Rachel says of her own personal taste. 'It's the intrinsic authenticity that's important but also because I'm trained to appreciate how they're formed as opposed to lab-grown ones.'

While acknowledging that lab-grown diamonds have the same chemical composition so they should structurally wear or last' Rachel insists these will have no resale value.

'We get people trying to sell lab-grown diamonds and we just won't take them in,' she says bluntly.

'In the industry especially, you don't want to be seeing fake anything, artificial or synthetic,' she says. While conceding that people want a bargain, Rachel suggests jewellery hunters would be better off looking to auctions for value.

'That's where the auction comes in you are getting the authentic thing for a bargain price,' she says.

Rachel sees parallels between the fatigue with fast fashion and the rise of second-hand clothing, and the increasing appetite for quality, pre-loved jewellery.

'Having a one-off piece of history is much better than getting a €100 thing you're going to forget about someday. You'd rather invest in good quality or timeless pieces,' she says.

For those considering making a bid, she suggests exploring retail jewellers first, so you can get an idea of the bargain you're getting at auction.

She also encourages trying on pieces, especially bangles and bracelets, which can be tiny.

Auctions also offer the opportunity to acquire items which have come back into style at competitive prices, like brooches, charm bracelets and pearls.

'You can get pearls for very good value at auction. We're talking €25k - €35k under €100 for a necklace or earrings and they just elevate an outfit. They suit everybody, they're very simple but there's something about pearls: they're supposed to reflect the light onto your skin and make you look a bit more radiant,' Rachel says.

The reasons that people consign are varied but Rachel says the auction houses have a theory as to why things end up in their sales.

'There's a running joke in the auction world that it's the three Ds - death, divorce or debt.' Alternatively, sometimes people simply want to upgrade an engagement ring on a significant anniversary: going from a one carat stone to a two carat to mark a big anniversary.

For the gemmologist, dealing with unique, beautiful pieces never loses its allure. Diamonds may be a girl's best friend, but a genuine gem with a great price or story, is even better.

If you want to indulge your inner Liz Taylor, you can explore Adam's Blackrock auction online at adamsblackrock.ie.ie or at the viewing in 17 Kildare Street, Dublin 2 from May 15 to 19. Rachel will be at the viewings in person too.

1. Only go to reputable and professional auction houses, jewellery shops or websites.

2. Read up on your preferred eras and their design styles, metals, gems, and cuts.

3. Don't get carried away by the romance of buying antique/ vintage and remember the old adage, 'buyer beware'.

4. Research hallmarks which indicate country of origin and the metal content. Older pieces don't necessarily have them as they weren't legally required until the 1970s. Do check that the hallmarks (if present) are genuine. Each country has its own marks as do some makers and retailers.

5. Do an inspection to check settings, claws around stones and chips or nicks in the stones. Look at the back as it will reveal repairs or alterations. Always ask for a condition report from the auction house.

6. Check if the piece has been professionally repaired, resized or re-polished. Older pieces will have been worn and loved so may have experienced some of the above. This doesn’t necessarily detract from the value as long as the work is appropriate.

7. Question the authenticity — some eras like the Belle Époque and Art Deco are widely copied. Copies are not as well made, and lack of visible wear.