8 Reales Felipe IV 1646 (Silver Cob): Value & Prices

If you inherited an oddly shaped, roughly cut silver coin stamped 1646, you likely have a Mexican 8 Reales cob from the reign of Felipe IV. In 2026, worn examples trade from around 150 to 400 USD, while sharp pieces with a clear date and assayer mark can reach several thousand. The value comes from the readable date and strike, not the age alone.

What you actually have

The 1646 8 Reales is a macuquina, the Spanish term for a cob: a hand-struck silver coin made in the Casa de Moneda (Mint) of Mexico City. Workers cut a chunk of silver, adjusted it to the legal weight, then struck it with a hammer and die. That process is why no two are identical and why the edges look chopped and irregular.

This is the coin the English-speaking world knew as the piece of eight, the silver dollar of global trade in the 1600s. It circulated everywhere from Manila to London.

Technical specs (keep these exact)

Spec	Value
Denomination	8 Reales
Ruler	Felipe IV (reigned 1621 to 1665)
Date	1646
Mint	Mexico City (Casa de Moneda)
Weight	25.64 grams
Silver fineness	.900 (90% silver)
Diameter	43 millimeters
Type	Hand-struck silver cob (macuquina)

At .900 fineness and 25.64 grams, the coin holds roughly 0.74 troy ounces of pure silver. That gives it a melt floor: even the most worn, damaged example is worth at least the value of its silver content, which moves with the spot price. As collectible coins, though, genuine cobs almost always sell well above melt.

What drives the price

Age is not what makes this coin valuable. Millions of pieces of eight were struck across the 1600s, so scarcity depends on condition and legibility, not the calendar.

Three things move the number up:

1. A readable date. Many cobs were struck off-center or on undersized planchets, so the year is missing entirely. A coin where 1646 is clearly visible is worth a real premium over a dateless one.
2. A visible assayer mark. The mark of the mint official who verified the silver helps pin the coin to a specific issue and adds value when identifiable.
3. Strike and relief. A cob with sharp cross, shield, and pillars details commands far more than a flat, corroded blob of the same weight.

Real-world value ranges (USD)

Condition	Typical range (USD)
Heavily worn, dateless or corroded	120 to 300
Legible date, moderate wear	300 to 900
Sharp strike, clear date and assayer	1,000 to 3,000+
Certified high-grade or shipwreck-provenance	Several thousand

Certified Spanish-colonial cobs with documented shipwreck recovery (from wrecks like the Atocha or the 1715 Fleet) can carry a premium for the provenance and the certificate, independent of grade.

The myth: "it's 375 years old, it must be worth a fortune"

Old does not mean rare. A worn, dateless 8 Reales cob is a common item in the colonial-silver market and sells for a few hundred dollars. The pieces that break into the thousands are the well-struck, dated, attributable examples. Do not assume yours is the rare one until an expert confirms the date, assayer, and authenticity.

How to tell if yours is genuine

Counterfeit and cast copies of Spanish cobs are everywhere, and precious-metal fakes are common because the melt value is real.

• Weigh it. Use a jewelry scale. A genuine full-weight 8 Reales is about 25.64 grams. Significantly light means it was clipped, holed, or fake.
• Measure it. Around 43 millimeters across at the widest point.
• Look at the strike. Real cobs show crisp, hand-struck detail, not the soft, mushy surfaces of a cast copy. Casting seams on the edge are a red flag.
• Check the design elements. The shield, cross, and mint and assayer marks should match documented 1646 Mexico types. Style errors give away many fakes.
• Be suspicious of bargains. Any offer far below the silver value is almost certainly a fake or a scam.

For a coin this valuable and this often faked, professional grading and authentication (NGC or PCGS) is worth the cost. A certified, slabbed cob sells faster and higher.

Errors and varieties

Genuine mint errors (off-center strikes, die rotation, double strikes, and recognized varieties) can multiply the value when verified. Most "errors" people spot on social media are post-mint damage: dents, corrosion, and scratches, not factory flaws. If you think yours has a real error, post clear photos in the Pesoteca forum and let experienced collectors weigh in.

Where to sell it

Sell where buyers know Spanish-colonial silver and will value it in person:

• A verified dealer from the Pesoteca shop directory can appraise it on the spot and quote a fair price.
• The Pesoteca buy-and-sell forum connects you directly with collectors who want cobs.

Before you sell, photograph the obverse, reverse, and edge in good light, note the weight, and compare against the ranges above. Never dump it on the first Facebook offer, and never sell to anyone who won't let you verify the piece and its weight first.

Got a 1646 cob or another colonial 8 Reales sitting in a drawer? Post your photos and weight in the Pesoteca forum and get a read on the date, assayer, and real value before you decide what to do with it.

This piece belongs to the reign of Felipe IV of Spain (1621-1665). King during the Thirty Years' War and the separation of Portugal. His royal favorite was the Count-Duke of Olivares.

The government of New Spain in 1646 was in the hands of Garcia Sarmiento de Sotomayor, Count of Salvatierra, during the mining boom of New Spain.

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

The Mexico City Mint (crowned Mo mark) operated from 1535 as the first mint in the Americas. Throughout the 17th century it struck cobs almost without interruption, being the main point of issue for struck silver in the Spanish empire. 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.

A year of tensions between the Count of Salvatierra and the Royal Audiencia over fiscal control.