8 Reales Carlos IV 1789: Value & Prices

If you inherited or found a 1789 Mexican 8 Reales with "CAROLVS IV" on it, here is the straight answer: in circulated condition it is worth roughly 200 to 250 USD, but a sharp uncirculated example has sold for around 3,200 USD. Most of that value comes from grade, not age, and this specific date has a quirk that collectors pay attention to.

What this coin is

The 8 Reales was the Spanish colonial silver dollar, struck at the Mexico City mint (marked Mo) when Mexico was part of the Spanish empire. It is a large silver piece, and the 1789 date sits at a transition moment.

Carlos III of Spain died on December 14, 1788. His son Carlos IV succeeded him, but the new dies took time to arrive from Spain. The result: this coin carries the name and numeral of the new king (the legend reads CAROLVS IV DEI GRATIA) while still showing the laureate bust of his father, Carlos III, on the front. That mismatch is what separates this piece from an ordinary colonial 8 Reales. Collectors call it a transitional or "imaginary bust" type, and it is the reason this date draws extra attention.

Is it silver? Yes.

This is a genuine silver coin, and that gives it a price floor no matter the condition.

Spec	Value
Metal	Silver
Fineness	0.900 (international catalogs cite about .903)
Weight	26.89 g
Diameter	39 mm
Pure silver	about 24 g (roughly 0.78 troy ounces)

At silver prices in 2026, the metal alone is worth somewhere in the low tens of dollars per coin. But for this piece the melt value is almost never the number that matters. The coin as a collectible is worth much more.

What it is actually worth

Price is driven by grade (condition) and by how clearly the bust of Carlos III reads. Auction and catalog data show a wide spread:

Grade	Approximate value	Source
Circulated (VF)	around 200 to 250 USD	Numista, April 2025
Uncirculated (MS62)	around 3,000 to 3,200 USD	Numista, April 2025

So the difference between a worn example and a crisp uncirculated one is more than ten times the money. A coin where the bust, the shield, and the fine detail are still sharp sits at the top of that range. A coin that has been cleaned, scratched, or worn smooth sits at the bottom, or below it.

Watch the numeral variety

Not every 1789 8 Reales is the same coin. Some examples spell the numeral as IV and others as IIII. These are distinct varieties and they can trade at different prices. Look closely at how the numeral is engraved on your piece before you assume its value, because collectors do.

How to tell if yours is genuine

Colonial silver is faked, so run these checks before you buy or sell:

1. Weight and size. It should weigh about 26.89 g and measure 39 mm across. A coin that is light or off-size is a red flag.
2. The reverse. You want the crowned shield between two pillars, with the banner reading PLVS VLTRA, the Mo mint mark, the 8R denomination, and the assayer initials FM.
3. The bust. Remember, the front shows Carlos III even though the legend names Carlos IV. That is correct for 1789, not an error.
4. The ring. Real silver has a distinct high tone when tapped, though this test alone proves nothing.

If anything looks off, get it checked by a specialist before money changes hands.

What Mo and FM mean

Mo is the mint mark for Mexico City, where the coin was struck. FM are the initials of the assayers responsible for the silver fineness during that period. Both appear on the reverse next to the shield and pillars. They confirm the coin is a Mexico City product, which is what you want to see.

Where to sell

Because value on this coin swings so hard with grade, sell to someone who actually knows colonial silver rather than a general pawn shop that will pay you melt. Pesoteca keeps a directory of dealers who buy and sell colonial silver and can give you a grade-based valuation. If you want to see how this piece fits the wider series, browse the colonial 8 Reales series and the colonial era catalog.

Have a 1789 8 Reales in hand and not sure whether yours is the IV or the IIII variety? Post clear photos of both sides on the Pesoteca forum and let collectors weigh in before you sell.

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 led by 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 royal shield crowned with the Golden Fleece. The edge is laureate or corded, and every example was struck on a screw press, with Latin legends spelling out the monarch's titles and dignities.

The Mexico mint had migrated to the bust pattern in 1772. Under Carlos III and Carlos IV the highest annual output of struck silver in the viceroyalty was recorded, fueling trade with the Philippines via the Manila Galleon and the payment of the situado to the Antilles. The assayer's initials declared on the piece are FM, an official of the Royal Treasury charged with certifying the silver fineness (0.930 and later 0.903) per viceregal standard.

The Krause catalog references this piece under KM#106, useful for cross-checking the listing against international auction records.

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