SEOUL, Dec. 19 -- A 20-year-old air conditioner has unexpectedly become one of South Korea's most talked-about vintage items after a viral video revealed that its logo was made of pure gold, sparking a nationwide hunt through homes, storerooms and scrap piles.

The YouTube clip, titled "Is there gold in air conditioners?", shows a Seoul-based gold shop owner known as Ringring Unnie examining a bundle of battered metal letters brought in by a customer. Holding up the pieces, she asks: "What is this?"

"It was removed from an LG Whisen air conditioner. It was the logo attached to the front of the air conditioner," the customer replies.

"The delivery person said it was gold, and the advertisement also mentioned it was gold. At the time, the...