8 Reales Carlos II 1670 (Silver Cob): Value & Prices

If you inherited or found a 1670 Mexico 8 Reales from the reign of Carlos II, here is the short answer: a genuine, worn example is typically worth from about USD 300 to 800, while sharp, well-struck or certified pieces climb into several thousand dollars. In 2026, this is one of the more collected Spanish colonial silver coins, and value depends almost entirely on authenticity, strike quality, and grade.

What you actually have

This coin is an 8 Reales struck in 1670 at the Mexico City Mint (the Casa de Moneda de México), the largest silver producer in the entire Spanish Empire at the time. It carries the assayer's initial G, the mint official who certified the metal's purity.

The 8 Reales was the famous "piece of eight," the international trade coin that circulated worldwide for centuries. Mexico City minted more of them than anywhere else.

Technical facts to confirm on your piece:

• Metal: silver, 0.900 fineness (90% pure)
• Weight: 26.85 g
• Diameter: 40 mm
• Edge: plain (no lettering or reeding)
• Catalog reference: KM#46

One important note: coins of this era from Mexico were often struck as cobs, irregular hand-hammered blanks rather than the perfectly round machine coins you may expect. An irregular shape does not mean it is fake. It means it is early colonial. A perfectly round, sharp 1670 8 Reales should actually raise your suspicion, not lower it.

How much is it worth in USD

There is no single price. Spanish colonial cobs are valued piece by piece, because strike quality on hand-hammered coins varies enormously. Two coins of the same date can differ tenfold in value based on how much of the design is visible.

Condition	What it looks like	Approximate value (USD)
Heavily worn / partial strike	Date and design barely readable	250 to 450
Average circulated cob	Cross and shield visible, some detail	450 to 1,000
Sharp strike, full date	Clear assayer and mint marks	1,000 to 3,000
Certified high grade (NGC/PCGS)	Strong detail, verified genuine	3,000 and up

Because the coin contains about 24 grams of pure silver, it always has a floor value at melt, currently a few dozen dollars depending on the silver spot price. No genuine 1670 8 Reales is worth less than its silver content, so ignore anyone offering you "just scrap value."

Is it rare?

Rarity here is not about the date alone. Mexico City struck 8 Reales in enormous quantities, so the type is not scarce. What is scarce is a well-preserved, fully-struck, verifiably genuine example. Most surviving cobs are weakly struck, clipped, corroded from long burial or shipwreck salvage, or outright counterfeit. A coin with a clear full date, readable assayer G, and strong cross is where the real money is.

The counterfeit problem (read this before you buy or sell)

Colonial 8 Reales are among the most faked coins in the world. Cast copies, tourist replicas, and modern fakes flood online marketplaces. Before you assign any real value:

1. Weigh it. A genuine piece is close to 26.85 g. Cast fakes are often too light or too heavy.
2. Measure it. Around 40 mm in diameter.
3. Check the metal. Real ones are 0.900 silver. Many fakes are base metal that fails a magnet or acid test.
4. Look at the strike. Genuine cobs show hand-struck irregularity, not the soft, blurry surfaces of a cast copy.
5. Be suspicious of any deal well below silver value. That is the classic fake giveaway.

For a coin at this price level, third-party certification from NGC or PCGS is worth the fee. A slabbed, authenticated example sells faster and for more, and it removes the buyer's biggest fear.

Where to sell it

• A verified numismatic dealer from the Pesoteca shop directory will appraise it on the spot with no middleman markup.
• The Pesoteca buy-and-sell forum connects you directly with collectors who know colonial silver.
• For a high-grade or certified piece, an established auction house (Heritage, Stack's Bowers) reaches the strongest buyers.

Before selling, photograph the obverse, reverse, and edge in good light, and note the weight from a jewelry scale. Do not dump it to the first Facebook buyer. Colonial silver is exactly the category where uninformed sellers leave the most money on the table.

Think you might have a genuine 1670 8 Reales, or not sure if yours is a cast copy? Post clear photos of both sides and the edge in the Pesoteca forum and let collectors who handle these coins weigh in.

This piece belongs to the reign of Carlos II of Spain (1665-1700). The last king of the House of Austria in Spain. His death without issue triggered the War of the Spanish Succession (1701-1714).

The government of New Spain in 1670 was in the hands of Antonio Sebastián de Toledo, marquis of Mancera, at the end of his viceroyalty, with works on the Metropolitan Cathedral.

The numismatic type of the piece is cob (macuquina), also called hammer-struck coin. The planchets were clipped with shears from a silver bar and struck between manual dies, so no cob has an edge or a perfectly circular shape. It circulated as a reference trade coin throughout the Atlantic for more than two centuries.

The Mexico mint (crowned Mo mark) operated from 1535 as the first mint in America. During the 17th century it struck cobs almost without interruption, being the main point of issue of struck silver in the Spanish empire. The dies were signed by the Mexico mint assayer active in the period, an official charged by the Royal Treasury with certifying that the silver fineness met the viceregal standard.

Colonial catalogs trace this piece within the families of the Mexico Real de a ocho, with prices that respond to rarity by year and assayer's signature.

Year of Felipe IV's death consolidated, with Carlos II under the regency of Mariana of Austria in Spain.