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The 1990-S Washington Quarter is worth anywhere from $2 in typical proof condition to over $5,000 for rare high-grade specimens. While most found in change are common, San Francisco “S” mint marks are special collectibles that often hide significant value for lucky finders.
| Condition / Grade | Estimated Value |
|---|---|
| Proof-65 (Typical) | $2.00 – $5.00 |
| Proof-69 (Deep Cameo) | $15.00 – $25.00 |
| Proof-70 (Perfect) | $250.00 – $600.00 |
| Error Varieties | $50.00 – $5,000+ |
Understanding the 1990-S Mint Mark Quarter
If you have discovered a 1990 quarter with a tiny “S” located to the right of George Washington’s ponytail, you have a Proof coin. Unlike the “P” (Philadelphia) or “D” (Denver) quarters meant for buying groceries, the San Francisco Mint produced these specifically for collectors. They weren’t intended to circulate, which is why finding one in your pocket change is quite a surprise. To quickly determine if yours is a high-value rarity, using a top coin identifier app can save you hours of manual research.
These coins were struck using polished dies and specially prepared blanks. This process results in a mirror-like background (the fields) and a frosted, white appearance on Washington’s portrait (the devices). In the world of numismatics, this contrast is known as a “Cameo” or “Deep Cameo” effect. When you use CoinKnow, you can see high-definition examples of these finishes to compare against your own find.
While over 3 million of these were minted, their value depends entirely on their state of preservation. Because they are Proofs, any scratch, fingerprint, or dullness significantly drops the price. However, if you find one that looks “perfect,” you might be looking at a significant payday.
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The Price of Perfection: 1990-S MS/PR Grades
In the grading world, Proof coins are rated from 1 to 70. A 1990-S quarter in PR65 is relatively common and might only buy you a cup of coffee. However, the market shifts dramatically when you reach the “Perfect 70” mark. Very few coins survive thirty years without a single microscopic flaw. You can verify current 1990 Washington Quarter market prices for high-grade specimens to see how they fluctuate based on auction demand.
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The 1990-S Proof is composed of a copper-nickel “clad” sandwich. Unlike earlier 1964 quarters, it contains no silver. Despite the lack of precious metal, the value is driven by “registry set” collectors—enthusiasts who compete to own the highest-graded version of every year’s quarter. This competition is why a PR70 Deep Cameo can sell for hundreds or even thousands of dollars at major auction houses like Heritage or GreatCollections.
| Grade Level | Market Price Range |
|---|---|
| PR67 Deep Cameo | $8 – $12 |
| PR68 Deep Cameo | $14 – $22 |
| PR69 Deep Cameo | $25 – $45 |
| PR70 Deep Cameo | $250 – $1,200+ |
Valuable Errors and Varieties to Look For
Beyond the standard grade, the real “jackpot” for the 1990-S Washington Quarter lies in mint errors. Because the San Francisco Mint has higher quality control, errors are extremely rare, making them highly sought after. One notable error type is the “Off-Center Strike,” where the coin blank was not properly aligned, resulting in a partial image.
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Another fascinatng error is the “Double Denomination” error, such as a 1990-S quarter struck on a penny or dime planchet. These are exceptionally valuable, often reaching four figures. If you suspect your coin has an unusual thickness or weight, CoinKnow provides a database of known errors to help you identify these anomalies instantly. Checking the 1990 quarter value information for error sales will show you that even “common” years can produce five-figure treasures.
How Condition Impacts Your 1990-S Quarter Value
For the everyday American, the “condition” of a 1990-S quarter found in circulation is likely “Impaired Proof.” This means the coin was once in a shiny protective plastic case from the Mint, but someone broke it out and spent it. Once a Proof coin touches other coins or fingers, it develops “hairlines” (micro-scratches).
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An impaired proof is generally worth only its face value ($0.25) or a small premium ($0.50-$1.00) to a casual collector. To achieve the values listed in price guides, the coin must be “Brilliant Uncirculated.” It should have no visible wear, no dulling of the mirror finish, and no signs of being cleaned. Cleaning a coin actually destroys its value, so never scrub your 1990-S quarter with polish or cloth!
Using CoinKnow allows you to take a photo of your coin and get an instant assessment of its condition. This is a crucial step before spending money on professional grading services like PCGS or NGC, which can cost $30-$50 per coin.
| Surface Quality | Collectibility Level |
|---|---|
| Mirror-like, no scratches | High (Investment Grade) |
| Faint scratches, still shiny | Medium (Entry Collector) |
| Dull, heavy scratches | Low (Face Value) |
The Rarity of Sample and Experimental Strikes
In very rare instances, experimental planchets or “trial pieces” from the late 80s and early 90s find their way into the public. While most 1990-S quarters are the standard clad composition, numismatists keep an eye out for coins with off-metal colors or unusual weights. A standard 1990 quarter should weigh 5.67 grams. If your “S” mint quarter weighs significantly more or less, it might be an unrecorded experimental strike.
These rarities are the holy grail for Washington Quarter enthusiasts. While the chance of finding one is slim, the payout can be life-changing. Always keep your 1990-S quarters separate from your spare change until you’ve had a chance to weigh them and inspect them under a 10x magnifying loupe.
Your Old Coin Could Be Valuable!
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Summary: Should You Sell Your 1990-S Quarter?
The decision to sell or keep your 1990-S Washington Quarter depends on its grade. If you have a standard proof that looks nice but isn’t perfect, it makes a great “heirloom” coin to start a collection for a child or grandchild. If you believe you have a PR70 (a coin that looks like a perfect mirror under magnification) or a clear striking error, it is absolutely worth seeking a professional appraisal.
Most local coin shops will buy these for a small premium over face value, but to get top dollar, online auctions or specialized coin shows are your best bet. Remember to keep the coin in a PVC-free flip or a hard plastic capsule to prevent the copper edges from tarnishing over time.
FAQ
Q: Does a 1990-S Quarter contain silver?
A: No, standard 1990-S Proof quarters are made of a copper-nickel clad composition. The San Francisco Mint did not start producing Silver Proof sets again until 1992.
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Q: How can I tell if my 1990 quarter is a Proof?
A: Look for the “S” mint mark and a “mirror-like” finish. Standard quarters from Philadelphia (P) or Denver (D) have a duller, matte-like luster compared to the reflective surface of a Proof.
Q: What is a “Camper” or “Deep Cameo” 1990-S quarter?
A: These terms describe the contrast between the shiny background and the frosted portrait. “Deep Cameo” (DCAM) is the highest level of contrast and is the most desirable for collectors.
Q: Is it worth grading a 1990-S Washington Quarter?
A: Only if it appears to be in perfect condition. Professional grading costs can exceed the value of the coin unless it achieves a PR69 or PR70 grade. Use an app to estimate the grade before sending it off.