What Makes a Coin Valuable
How mintage, condition, and demand interact — and why age alone means very little.
Read the guideCollector's Corner
U.S. Mint Marks: Where to Find Them and Why They Matter
A single small letter can be the difference between a common coin and a genuinely scarce one. Here's where mint marks live on each denomination, what each mint's output is known for, and how to read a mark without fooling yourself.
The basics
What a mint mark actually tells you
A mint mark identifies the facility that struck the coin. Because each facility produced different quantities in different years, the mark — combined with the date — is what determines whether a coin is common, semi-key, or key.
Two coins that look identical across a table can be worth a few dollars and a few thousand dollars respectively, purely because of that letter. The 1893 Morgan dollar is a good example: the Philadelphia issue is scarce but attainable, while the 1893-S is one of the most valuable regular-issue Morgan dollars in existence. Nothing about the design differs. Only the mark does.
That value gap is also why mint marks are the single most commonly faked detail on U.S. coins. Added, removed, and re-engraved mint marks have circulated for over a century. Any high-value date-and-mint combination is a coin we recommend buying certified — or having examined in person before money changes hands.
The mints
Eight letters, eight facilities
| Mark | Mint | Years | Worth knowing |
|---|---|---|---|
| P (or none) | Philadelphia | 1793 – present | The original U.S. Mint. For most of its history Philadelphia struck coins with no mint mark at all. A 'P' appears on wartime nickels (1942–1945), and on most denominations from 1980 onward — though the cent still carries no mark. |
| D | Denver | 1906 – present | The largest producer of circulating coinage today. Note that 'D' was also used by the Dahlonega mint decades earlier — but only on gold coins, and only through 1861, so the two never overlap. |
| S | San Francisco | 1854 – present | Struck circulating coinage into the 1970s and has produced most U.S. proof coinage since 1968. Older 'S' issues in high grade are frequently scarcer than their Philadelphia counterparts. |
| CC | Carson City | 1870 – 1893 | Short-lived, low-mintage, and hugely collected. Carson City Morgan dollars and Seated coinage carry a strong premium, which also makes them a common target for counterfeit and added mint marks. |
| O | New Orleans | 1838 – 1861, 1879 – 1909 | Known for softly struck silver — an 'O' Morgan dollar with a weak strike is normal, not damage, and grading services account for it. |
| W | West Point | 1984 – present | Primarily bullion and commemorative issues. A handful of 'W' quarters were released into circulation in 2019–2020, which is worth checking pocket change for. |
| C | Charlotte | 1838 – 1861 | Gold only, in modest quantities. Any genuine Charlotte gold piece is a significant coin. |
| D (Dahlonega) | Dahlonega | 1838 – 1861 | Georgia gold, gold only, and all scarce. Distinguished from Denver by denomination and date, never by the letter alone. |
Where to look
Mint mark locations by denomination
Positions moved over time — often when a design changed or when the Mint consolidated marks onto the obverse in 1968. When in doubt, check both sides at low magnification before concluding a coin has no mark.
- Lincoln cent
- Below the date on the obverse. Philadelphia cents carry no mark; 1909-S and 1909-S VDB are the famous exceptions to look for.
- Jefferson nickel
- Right of Monticello (1938–1964), then near the date from 1968 on. Wartime silver nickels (1942–1945) carry a large P, D, or S above the dome — the only nickels with a Philadelphia mark.
- Mercury & Roosevelt dimes
- Reverse, near the base of the fasces on Mercury dimes; reverse near the torch on early Roosevelts, moving to the obverse above the date in 1968.
- Washington quarter
- Reverse below the eagle through 1964; obverse right of the ribbon from 1968 onward.
- Walking Liberty & Franklin halves
- Obverse lower left on some 1916–1917 Walkers, otherwise reverse lower left. Franklin halves carry the mark above the Liberty Bell beam.
- Morgan & Peace dollars
- Reverse, below the wreath (Morgan) or below the word ONE on the eagle's perch (Peace). This is where CC, O, and S marks appear — and where you should look most carefully.
- Classic U.S. gold
- Reverse below the eagle on most types; Saint-Gaudens double eagles carry the mark on the obverse above the date.
Practical technique
How to read a mint mark properly
- Use a 5x to 10x loupe in strong, angled light. Higher magnification is not better for this — it narrows your field and flattens the surface detail you need.
- Hold the coin by its edge, over a soft surface. Never touch the faces, and never clean a coin to make a mark easier to read.
- Compare the mark's font and position to a known genuine example of the same year and type. Added mint marks often sit slightly off-position or show a seam under raking light.
- Look for tooling: disturbed metal, a flat halo, or a mark that appears crisper than the surrounding devices on a worn coin.
- On heavily circulated coins, a mark may simply be worn away. That is not the same as a Philadelphia issue — the position and any remaining trace still matter.
- For anything approaching key-date value, stop and get a second opinion before buying. Certification exists precisely for this problem.
Worth checking
Branch-mint issues collectors watch for
This is not an exhaustive key-date list — it's a shortlist of combinations that turn up in inherited collections around the Lowcountry more often than people expect.
- 1909-S and 1909-S VDB Lincoln cents — the VDB initials appear at the base of the reverse on the earliest issues.
- 1914-D and 1931-S Lincoln cents.
- 1916-D Mercury dime — the single most valuable regular-issue coin in the series, and heavily counterfeited.
- 1932-D and 1932-S Washington quarters — the first year of the series, in small numbers.
- 1921-D and 1893-S Morgan dollars, and any Carson City Morgan.
- 1928 and 1934-S Peace dollars.
- Any Charlotte, Dahlonega, or Carson City gold, in any grade.
Not sure what's sitting in the folder you inherited? You don't need to identify anything before you come in. Bring it as-is and we'll go through it with you — see inherited collections or start an evaluation.
Keep reading
Related guides
How Coin Grading Works
The Sheldon scale and what separates a nice circulated coin from an uncirculated one.
Read the guidePCGS vs. NGC
When third-party certification is worth the cost, especially for key dates.
Read the guideFound a mint mark you can't place?
Bring the coin in and we'll look at it under the loupe with you — no charge for a conversation, no obligation to sell.