8 Reales Carlos IV 1789: Value & Real Prices

If you inherited an 1789 Mexican 8 Reales of Carlos IV, here is the honest answer: it is a genuine silver coin with real collector demand, and in 2026 even a worn example is worth more than its melt value, typically from 50 to a few hundred USD depending on grade. The rare, high-grade pieces climb into four figures.

This is one of the most historically important coins ever struck. The Spanish 8 Reales (the "piece of eight") was the dominant trade coin of the world for centuries, and the Mexico City mint was its largest producer. That means two things for you: your coin is genuinely old and interesting, and it was minted in huge numbers, so most surviving examples are common. Rarity here comes from condition, not age.

What you actually have

The coin is dated 1789, from the transition at the start of Carlos IV's reign. A well-known quirk: the 1789 and 1790 issues still carry the bust of Carlos III while naming Carlos IV in the legend, because the new portrait dies had not arrived yet. Collectors call these "transitional" or "armored bust" types, and they are more sought after than the later, standard Carlos IV portrait.

Feature	Detail
Denomination	8 Reales
Year	1789
Mint	Mexico City (Mo mint mark)
Assayer initials	FM
Metal	Silver, .903 fine
Weight	26.89 g
Diameter	39 mm
Edge	Incuse (patterned)
Catalog reference	KM#106

The FM initials are the assayer's mark, the official who guaranteed the silver content. The silver content alone gives the coin a price floor: at roughly 0.78 troy ounces of pure silver, the melt value moves with the silver market, and no genuine example should ever sell below that.

What it's worth in 2026

Because millions of 8 Reales were struck across the colonial period, value tracks condition closely. A dark, worn coin that spent years in circulation is worth a modest premium over silver. A sharp, lightly circulated coin with clear detail on the bust and shield jumps in value. Certified Mint State examples are where the real money is.

Condition	Approximate value (USD)
Heavily worn / damaged	30 to 60 (near melt)
Circulated, clear detail	80 to 250
Lightly circulated (About Uncirculated)	300 to 700
Certified Mint State (NGC/PCGS)	1,000 and up

Transitional 1789 pieces with the Carlos III bust tend to sit at the higher end of each band because of the added collector interest. Exceptional, high-grade coins with attractive toning have brought several thousand dollars at major auction houses like Heritage and Stack's Bowers.

The catch: chop marks and cleaning

Two things commonly hurt value on these coins. First, chop marks: small stamps that Asian merchants punched into trade dollars to verify silver. They tell a great story but usually lower the price for standard collectors. Second, cleaning: many old 8 Reales were polished at some point, which leaves hairline scratches and kills the value for grading. If the surface looks unnaturally shiny or scrubbed, expect a discount.

How to check if yours is genuine

Colonial 8 Reales are among the most counterfeited coins in the world, both period contemporary fakes and modern cast copies. Before you get excited or before you buy one, do this:

• Weigh it. A real example is close to 26.89 g. A cast fake is often light or heavy.
• Measure the diameter. It should be about 39 mm. Use a caliper.
• Check the edge. The genuine coin has an incuse patterned edge, not a plain or seam-lined one. A visible seam around the rim is a red flag for a cast copy.
• Look at the detail. Cast fakes have soft, mushy lettering and often small bubbles or pitting in the fields.
• Verify the mint mark and assayer. It should read Mo (Mexico) and FM.

Any offer priced well below the silver value is almost certainly a fake or has a problem. When in doubt, submit it to a third-party grading service (NGC or PCGS) for authentication and encapsulation, which also raises the resale value.

Where to sell it

For the best outcome, use a verified coin dealer who can value it on the spot, or sell to collectors directly rather than dumping it to the first buyer online. Photograph the obverse, reverse, and edge in good light, and check the price range in the table above so you know what a fair offer looks like. For a coin with silver content, deal only with buyers who will show you the piece, its weight, and their reasoning. Because it is a precious-metal coin, verify before any money changes hands.

If you want a second opinion on grade, authenticity, or a possible transitional variety, post clear photos in the Pesoteca forum and let the community weigh in. Have an 1789 8 Reales sitting in a drawer? Share your photos and we'll help you figure out what it's really worth.

This piece belongs to the reign of Carlos IV of Spain (1788-1808). Son of Carlos III. His reign coincided with the French Revolution and with the Napoleonic Wars that ended in the abdications of Bayonne.

The government of New Spain in 1789 was in the hands of Manuel Antonio Florez, the close of his viceroyalty in New Spain.

The numismatic type of the piece is bust, introduced in 1772 under Carlos III. The obverse shows the king's portrait in the neoclassical fashion and the reverse the crowned royal shield with the Golden Fleece. The edge is laureate or corded and all examples were struck on a screw press, with Latin legends that spelled out the monarch's titles and dignities.

The Mexico City Mint had migrated to the bust pattern in 1772. Under Carlos III and Carlos IV the highest annual production of struck silver in the viceroyalty was recorded, feeding the trade with the Philippines via the Manila Galleon and the payment of the subsidy to the Antilles. The dies were signed by the assayer of the Mexico City Mint active in the period, an official charged by the Royal Treasury with certifying that the silver fineness met the viceregal standard.

Colonial catalogs track this piece within the families of the Mexico City Piece of Eight, with prices that respond to rarity by year and assayer signature.

The year of the accession of Carlos IV and of the French Revolution, two events that would mark the rest of the reign.