If you ever need a reminder of how much stuff there is in the world, don’t go to the mall — check out an antiques market. Every item for sale there, from silver spoons to vintage shoes to sapphire earrings, is testament to the fact that more than just diamonds are forever.

In the past few months, I’ve had the pleasure of touring two of the world’s greatest antiques markets, held in London’s Covent Garden and the San Telmo barrio of Buenos Aires. Both were overwhelming experiences.

A woven leather belt purchase at Buenos Aires's largest antiques market. (M.J. Prest/EthicalStyle.com)

Set up in Covent Garden’s Jubilee Hall (30 The Piazza, London WC2E 8RA) on Monday mornings, London’s biggest antiques market is almost too big to digest in a single day. Here you can find antique cufflinks and cameo pins in all conditions, from pristine to rusting. Bring a sharp eye and a lot of patience, because you’re going to be digging through a lot of junk. We were particularly enamored with the vintage costume and fine jewelry, including some exquisite collector’s items from the Edwardian era. Our only purchase, however, was a pair of oversize earrings made from peacock feathers, which we scooped up for a single quid ($1.60 in USD).

On Sundays, the San Telmo antiques market in Buenos Aires convenes in the Plaza Dorrego (Defensa 1098, San Telmo, Buenos Aires), the oldest public square in the city. Here you can spend your pesos on not just antiques but everything from handicrafts to leather goods to hand-wrought silver jewelry. While you browse the stalls, tango dancers perform in the square and pose for photographs with tourists.

Argentina’s leather is some of the best in the world so I was on the hunt for vintage leather goods. I ended up purchasing the vintage woven leather belt pictured above, which had at one point been treated with a distressed gold paint that was now artfully flaking off. It was in great condition but I negotiated the price down to 50 Argentinian pesos ($13.15 in USD).

One thing is for sure: Deals are to be had, but typically not on truly valuable items. In San Telmo, I examine a 100-year-old pair of European cut diamond stud earrings set in platinum. At .6 total carat weight, the asking price was $1,000 — too rich for my blood, but the price was fair. I admit, I wouldn’t expect to pay less for a pair of earrings of similar quality in a mall back home.

Want to give antiquing in your city a shot? In general, the one rule of thumb of antiquing is to go with your gut. There is no room for waffling when it comes to such extremely limited quantities. Treat what you find as one-of-a-kind, since it probably is. And chances are you get one shot to buy your newfound treasure before someone else scoops it up or the seller disappears into the ether.