8 Reales Carlos II 1670 (Mexico Mint): Value Guide

If you inherited or found a Spanish colonial silver coin dated 1670 with the name Carolus II, you have a genuinely old and potentially valuable piece. In 2026, an authentic 8 Reales of Carlos II struck at the Mexico City mint ranges from roughly 150 USD in low, corroded grades to several thousand USD for well-preserved, certified examples. The catch: condition and authenticity decide almost everything, and this is exactly the type of coin that gets faked.

This is not a modern peso. It is a hand-struck ("cob" or milled transitional) silver coin from the Spanish Viceroyalty of New Spain, minted in what is today Mexico City. That makes it one of the oldest coins most Americans will ever hold in a hobby collection.

What you actually have

The 8 Reales was the workhorse silver dollar of the Spanish empire, the direct ancestor of the US dollar. This particular issue was struck in 1670 under King Carlos II of Spain, at the Mexico City mint (ceca México), with assayer mark G.

Specifications you can verify at home:

• Metal: Silver, .900 fine (90 percent pure silver)
• Weight: 26.85 grams
• Diameter: 40 mm
• Edge: Plain (unmarked)
• Denomination: 8 Reales
• Era: Spanish Colonial / Viceroyalty of New Spain

An authentic piece should be close to that weight. If your coin weighs noticeably less than 26 grams or more than 28, treat it as suspect until it is verified.

What it is worth in 2026

With about 24 grams of pure silver, this coin has a hard floor: its melt value tracks the silver spot price and is never zero. That bullion floor is why even a beat-up example still sells. Above that floor, everything depends on grade, eye appeal, and how much of the design and date is legible, since 17th-century coins were struck by hand and are often uneven or clipped.

Condition	What it looks like	Approx. value (USD)
Poor / heavily worn	Date barely legible, corrosion, clipped	100 to 250
Good detail, honest wear	Design and date readable	300 to 900
High grade, strong strike	Full legends, sharp detail	1,500 to 4,000+
Certified premium example	NGC/PCGS graded, top condition	Several thousand and up

These are collector ranges for genuine, uncleaned coins. A cleaned or polished piece can lose half its value instantly, so if the surfaces look unnaturally shiny or scratched in fine lines, that hurts the price.

Because hand-struck colonial coins vary so much piece to piece, we do not quote a single fixed number. The safest read is to compare your coin's grade against the ranges above and confirm with a specialist before selling.

The myth to avoid

"It's from the 1600s, so it must be worth a fortune." Age alone does not make a coin valuable. Millions of 8 Reales were struck across the colonial period, and many survive. What drives real money is a legible date, a full strike, original uncleaned surfaces, and certification. A 1670 8 Reales that is corroded and cleaned is worth its silver plus a modest premium, not a fortune.

The bigger risk is the opposite: assuming yours is genuine when it is a modern reproduction or a cast fake. Spanish colonial silver is one of the most counterfeited categories in the hobby, precisely because collectors will pay for it.

How to tell if yours is genuine

1. Weigh it. A jeweler's scale should read near 26.85 grams. Cast fakes are often off.
2. The ping test. Balanced on a fingertip and tapped gently, real .900 silver rings with a high, sustained tone. Fakes sound dull and short.
3. Check the detail. Genuine struck coins show sharp, crisp devices even when worn. Cast copies look soft, grainy, or have a visible seam on the edge.
4. Get it certified. For anything you think is worth more than a few hundred dollars, submit it to NGC or PCGS. A certified slab confirms authenticity and grade, and it is what serious buyers pay premiums for.

Use our coin grading guide to place your coin in the right condition tier before you get quotes.

Where to sell it

Because this is a precious-metal colonial coin, sell only to buyers who inspect the piece and its weight, and verify before you pay:

• A verified numismatic dealer from the Pesoteca shop directory can appraise it in person and buy without middleman markups.
• The Pesoteca buy/sell forum connects you directly with collectors who know colonial silver.
• For high-grade certified examples, US auction houses that handle world coins (Heritage, Stack's Bowers) reach the deepest pool of buyers.

Photograph the obverse, reverse, and edge before listing, and never sell to the first offer online. Fakes circulate heavily in open marketplaces, so a serious buyer will always ask for weight and edge photos.

Have a 1670 8 Reales in hand and unsure whether the date is right or the surfaces are original? Post clear photos of both sides and the edge in the Pesoteca forum and let collectors who specialize in colonial silver weigh in before you sell.

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 heirs triggered the War of the Spanish Succession (1701-1714).

The government of New Spain in 1670 was in the hands of Antonio Sebastian de Toledo, Marquis of Mancera, at the end of his viceroyalty, with work underway on the Metropolitan Cathedral.

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

The Mexico City Mint (crowned Mo mint mark) operated from 1535 as the first mint in the Americas. Throughout the 17th century it struck cobs almost without interruption, being the main issuing point for struck silver in the Spanish empire. The assayer's initials declared on the piece are G, an official of the Royal Treasury charged with certifying the silver fineness (0.930 and later 0.903) under viceregal standard.

The Krause catalog references this piece under KM#46, useful for cross-checking the listing against international auction records.

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