Choosing between laboratory-grown and natural diamonds has become a dilemma for many young couples starting out on their journey together through life.“Both natural and lab-grown diamonds have a legitimate place within today’s market. But they offer very different value propositions,” says Elena McCrory of Adams Blackrock. She maintains that lab-grown diamonds provide exceptional visual appeal and allow buyers to acquire larger, high-grade colour diamonds at a significantly lower cost. “They are also often chosen by clients who sometimes perceive them as a more ethical alternative to newly mined diamonds,” she adds.However, McCrory is keen to point out that lab-grown diamonds have very little value on the secondary market. “We don’t value or consign any laboratory-grown diamonds at our auctions,” she says. In fact, Adams Blackrock has recently bought new equipment specifically to distinguish natural diamonds from lab-grown ones, so that they can be sure that what they are selling are naturally occurring diamonds. The difference between lab-grown and natural diamonds cannot be seen by the naked eye.John Weldon of Weldon Auctioneers on Cows Lane, Temple Bar, also has specialised equipment, which allows him to carefully distinguish between lab-grown and naturally-occurring diamonds. He does sell lab-grown diamonds at auction from time to time. “I think people should enjoy lab-grown diamonds for what they are. They offer an attractive and affordable way to wear a beautiful diamond. For example, I’ve sold them to clients who prefer not to travel with their more valuable jewellery but still want to wear a diamond on holiday. If it were to be lost or stolen, replacing it is far less costly than replacing a natural diamond of similar appearance.”In terms of resale value, Weldon says lab-grown diamonds generally do not retain the value of their original purchase price. “While there are always exceptions, the reality is that the intrinsic value of a lab-grown diamond ring is often in the gold or platinum setting, rather than the diamond itself,” he says.Weldon says lab-grown diamonds occasionally achieve higher-than-expected prices at auction, but in most cases, the precious metal is worth more than the lab-grown diamond itself.18ct white gold tennis bracelet (€6,000-€7,000), Adams Blackrock online auction 9ct white gold diamond necklace (€11,000-€12,000), Adams Blackrock online auction 18ct white gold pearl sapphire and diamond earrings (€4,000-€5,000), Adams Blackrock online auction Adams Blackrock has an 18ct white gold tennis bracelet with a continuous row of round brilliant-cut diamonds (€6,000-€7,000) in its forthcoming online auction, which ends on September 9th. A 9ct white gold diamond necklace with graduated round brilliant-cut diamonds (€11,000-€12,000); and a pair of 18ct white gold pearl sapphire and diamond earrings (€4,000-€5,000), are also for sale, alongside a selection of white gold diamond rings and bracelets. John Weldon chooses a mid-century diamond rivière necklace as one of the highlights in the jewellery, watches and gold coin auction at Weldon’s on Tuesday, August 26th, starting at 2pm. Set with a line of round brilliant-cut diamonds in 18ct gold, the necklace has a guide price of €45,000-€55,000. Its original retail price was €85,000. Rivière – French for river – necklaces are defined by a continuous line of round brilliant-cut diamonds that flow smoothly around the neck like a river. The production of the style is associated with the large-scale mining of diamonds in the Kimberley region of South Africa in the late 19th century. First worn by European royalty for formal occasions, diamond rivière necklaces have latterly become popular wearables among film stars at prestigious award ceremonies, and even for casual wear. The Weldon auction also has an 18ct gold diamond bracelet, set with 22 round brilliant-cut diamonds in rub-over settings surrounded by 132 round brilliant-cut diamonds (€10,000-€15,000).18ct gold diamond bracelet, (€10,000-€15,000), Weldon's online auction Round brilliant-cut diamonds, which maximise the stone’s internal light reflection, are generally the most expensive diamond shape on the market. Cutting the diamond to get the most amount of sparkle also involves more wastage, which can add to the cost. Viewing of items at Weldon’s auction takes place on Saturday and Sunday, August 22nd and 23rd, from noon to 5pm; Monday, August 24th, from 11am to 5pm; and Tuesday, August 25th, from 10.30am to 12.30pm.A heart-shaped pendant on a gold-plated chain (€5,000-€10,000) is one of the more intriguing lots among many jewellery items at the online auction on Saturday, August 29th, by Lynes & Lynes in Carrigtwohill, Co Cork.Originally owned by Titanic survivor Florence Agnes Angle, it was willed to an Irish friend (since deceased), whose family is now selling it. Angle, who was an English nurse, emigrated to America in 1906 with her husband, William. They travelled back to England to visit relatives in 1911 and boarded the Titanic at Southampton in April 1912. Florence was aboard Lifeboat 11 but her husband was among the estimated 1,500 passengers who died when the ship sank about 600km from Newfoundland. After returning briefly to New York, she returned to England and lived until she was 93. One of three lots of James Bond model cars (€40-€60) at Lynes & Lynes online auction The online auction, which is on view from Saturday, August 22nd until Friday, August 28th, has an extensive range of vintage items suitable for historic film or theatre productions. These include old typewriters, vintage radios and cameras, model cars, dolls and dolls houses. adamsblackrock.ie; jwa.ie; Lynesandlynes.com What did it sell for?Cartier Calibre Diver stainless steel gent's wristwatch Cartier Calibre Diver watchEstimate: €2,500-€3,500Hammer price: €3,700Auction house: Adams BlackrockVan Cleef & Arpels stainless steel lady's wristwatch Van Cleef & Arpels stainless steel watchEstimate: €700-€800Hammer price: €900Auction house: Adams BlackrockThe Painted Lake, Church Island, Lough Beg by JP Rooney The Painted Lake, Church Island, Lough Beg, JP RooneyEstimate: €1,100-€1,300Hammer price: €930 Auction house: Adams BlackrockWhite gold Tahitian pearl, sapphire and diamond earrings White gold Tahitian pearl, sapphire and diamond earringsEstimate: €3,000-€4,000Hammer price: €2,350Auction house: Adams Blackrock