You could have $20,000 in your pocket without knowing it: these quarters are a treasure

 A series of 25 cent coins manufactured between 1975 and 1976 to celebrate 200 years of US independence could skyrocket in value

How to detect them?

Most bicentennial coins were “clad,” meaning they were made from multiple metals such as nickel, copper and zinc, layered “like a sandwich,” the Mint explains. But some are made up of 40% silver, an important distinction because silver coins are rarer and therefore much more valuable.

The condition of the coin also influences its value, with those in perfect condition fetching the highest prices. The bicentennial coins were minted in three different locations: Philadelphia (809,784,016 coins), Denver (860,118,839), and San Francisco (4 million 40% silver, 11,000,000 uncirculated 40% silver, and 7,059. 099 coated).

Each coin bears the initials of the city in which it was minted. The silver 1976-S Bicentennial, which broke an auction record at nearly $20,000, was struck in San Francisco. Being made for circulation, it does not have the same shine as proof coins, so it can be difficult to recognize as a valuable object.

The Professional Coin Grading Service (PCGS, in English) placed the 1976-S Bicentennial silver at grade MS69 (the best being an MS70) on the Sheldon scale, meaning that some minor flaws were noted.

How to sell them?

From the webChronicle CollectiblesRemember that coins that are in perfect condition and are rare will fetch higher prices than coins that are in poor condition or are more common. It is also important to take the mintmark into account, and in this case, the 1976 coins minted in San Francisco will be the most valuable, followed by Denver and Philadelphia.

“Coins must be authenticated and graded by a professional before making a purchase. These points should also be adhered to before attempting to sell your coins: Have them professionally authenticated and graded before listing them for sale, and include plenty of details and close-up photos in your offer,” the site says.

Regarding the best places to sell them, Chronicle Collectibles especially recommends eBay, the Mavin price guide, Numista and the Etsy virtual store.

“You can often find good deals through Etsy, and Bicentennial pennies are common. Just be sure to look for listings with genuine coins and avoid fakes.”