The 2018-S Block Island National Wildlife Refuge Quarter is worth anywhere from $5 in circulated condition to $25 or more in pristine mint state — and the silver proof version can fetch $15 to $40 depending on its grade and eye appeal. If you found one of these in a proof set or tucked away in a collection, you may be sitting on a small but satisfying treasure.
best coin identifier app can help you quickly identify whether your 2018-S Block Island quarter is the standard clad version or the more valuable 90% silver proof edition — a difference that could mean real money in your pocket.
What Is the 2018-S Block Island Quarter?
The 2018-S Block Island National Wildlife Refuge Quarter is part of the America the Beautiful Quarters Program, a series launched by the U.S. Mint in 2010 that honors national parks and landmarks across the country. Block Island, located off the coast of Rhode Island, was the 46th design in the series. The obverse features the classic portrait of George Washington, while the reverse showcases a saltwater marsh scene — a nod to the refuge’s unique coastal ecosystem.
The “S” mintmark means this coin was struck at the San Francisco Mint, which is known for producing proof coins rather than coins meant for general circulation. Most 2018-S Block Island quarters were sold as part of proof sets — either the standard clad proof set or the 90% silver proof set. That means you’re unlikely to find one in your pocket change, but if you have one, it’s worth knowing exactly what you’ve got.
Clad vs. Silver: Why the Mint Mark Alone Isn’t Enough
Not all 2018-S Block Island quarters are created equal. The San Francisco Mint produced two major versions: the standard clad proof (copper-nickel) and the 90% silver proof. To the naked eye, they look nearly identical — both are struck to a mirror-like finish with frosted design elements. The real difference is in the metal content, and that matters quite a bit when it comes to value.
The clad proof version typically sells for $5 to $10 in a standard proof set, while the silver proof version commands a premium of $15 to $40 depending on condition and whether it’s been graded by a professional service like PCGS or NGC. Silver proofs in top grades (PR70 Deep Cameo) have sold for well over $40 at auction. If you’re not sure which version you have, weigh the coin — silver quarters weigh about 6.25 grams versus 5.67 grams for clad.
You can also check detailed 2018 quarter value information by mint mark and metal type to get a clearer picture of what your specific coin might be worth today.
2018-S Block Island Quarter Value Chart
| Version | Condition | Estimated Value |
|---|---|---|
| Clad Proof (S) | PR65–PR67 | $5 – $10 |
| Clad Proof (S) | PR69–PR70 DCAM | $12 – $25 |
| Silver Proof (S) | PR65–PR67 | $15 – $22 |
| Silver Proof (S) | PR69–PR70 DCAM | $30 – $45+ |
How to Get an Accurate Value for Your 2018-S Block Island Quarter
If you’re serious about knowing what your coin is worth, there are a few solid ways to find out. Professional coin grading services like PCGS and NGC can authenticate and grade your coin for a fee, which is worthwhile if you think you have a high-grade silver proof. For a quicker and free option, CoinHix is a popular app among collectors that lets you scan your coin and get real-time market data in seconds.
You can also browse recent sold listings on eBay to see what buyers are actually paying — not just what sellers are asking. For a deep dive into certified coin sales and auction records, current price data for America the Beautiful quarters including the 2018 Block Island series gives you a solid benchmark based on real transactions.
CoinHix is especially handy if you have a whole collection to sort through — it saves hours compared to looking up each coin individually.
Tips for Storing and Selling Your 2018-S Block Island Quarter
Proof coins are delicate. Even fingerprints can reduce a coin’s grade by one or two points, which translates directly into lost value. Always handle proof coins by their edges, and store them in acid-free holders or airtight capsules. If your coin is still in its original U.S. Mint packaging, keep it that way — the original box and certificate of authenticity add to the coin’s appeal for buyers.
When it’s time to sell, you have several options: coin dealers, online marketplaces like eBay or Etsy, or coin shows. For certified high-grade coins, Heritage Auctions and Stack’s Bowers are worth considering. And if you want to track your collection’s value over time, CoinHix lets you build a digital portfolio so you always know where you stand.
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FAQ
Q: Is the 2018-S Block Island quarter rare?
A: It’s not extremely rare, but it was never released into circulation. It was only available through U.S. Mint proof sets, which limits how many people have them. Silver proof versions are more limited and more desirable to collectors.
Q: How do I know if my 2018-S quarter is silver or clad?
A: The easiest method is to weigh it. Silver quarters weigh approximately 6.25 grams, while clad quarters weigh about 5.67 grams. You can also check the edge — silver quarters have a solid silver edge with no copper stripe visible.
Q: Where can I sell my 2018-S Block Island silver quarter?
A: You can sell it through eBay, a local coin dealer, or a coin show. For higher-value certified coins, consider Heritage Auctions. If you want a quick estimate before selling, use CoinHix to get a real-time market value so you don’t undersell.