8 Reales Resplandor 1887 San Luis Potosí: Value Guide

If you inherited or found an 8 Reales "Resplandor" from San Luis Potosí dated 1887, here is the honest answer: in worn condition it is worth its silver content, roughly 20 to 25 USD at current metal prices. In sharp, uncirculated condition or with a scarce mint mark, it can bring several hundred dollars. It is not a rarity in most grades, but it is real silver and it has a floor.

The "Resplandor" (Spanish for "radiance" or "sunburst") is the design most US collectors call the Mexican cap-and-rays 8 Reales. It was Mexico's workhorse silver dollar for most of the 19th century, and the 1887 San Luis Potosí issue is one of dozens of date-and-mint combinations struck across the country.

What you actually have

This is a large silver coin, about the size of a US silver dollar. The key specs, which you should verify before you buy or sell, are exact:

Spec	Value
Denomination	8 Reales
Year	1887
Mint	San Luis Potosí (mint mark Pi)
Metal	Silver, .900 fine (the standard was .9028)
Weight	27.07 grams
Diameter	39 mm
Edge	Reeded
Era	Restored Republic / Porfiriato

Obverse (front): a Phrygian cap over a sunburst of rays, with the word LIBERTAD ("liberty"). This cap-and-rays motif is why collectors call it the Resplandor.

Reverse (back): the Mexican eagle facing forward, standing on a cactus and eating a snake, with the legend REPÚBLICA MEXICANA. Below the eagle you should find the mint mark Pi for San Luis Potosí and the assayer's initials. Those two details confirm mint and year, so read them carefully.

How much is it worth in USD

Value on this coin comes down to two things: silver content and condition. It contains just under 0.786 troy ounces of pure silver, so it can never be worth less than melt.

• Well-worn (Good to Fine): essentially melt value, about 20 to 25 USD, tracking the silver spot price.
• Lightly circulated (VF to XF): roughly 30 to 60 USD, depending on eye appeal.
• About Uncirculated (AU): commonly 75 to 150 USD.
• Uncirculated (MS): several hundred dollars for a clean, original coin. High-grade certified examples of scarcer date-mint combinations can exceed 1,000 USD, but that is the exception, not the rule.

The San Luis Potosí mint (Pi) is a common issuing mint for this series, so an average 1887 Pi is not rare. The premium lives in grade. A gem uncirculated coin with full luster is worth many times a bag-worn one of the same date.

Because the coin is silver, its floor moves with the metal market. Check the live silver spot price before you settle on a number.

The myth to kill

A lot of people assume any 19th-century Mexican silver coin is a fortune. Most 8 Reales from common mints and years, including this one, are worth tens of dollars, not thousands. The pieces that break records are specific rare dates, rare mints, or top-population certified grades. "Old" does not mean "valuable." Rare and well-preserved does.

How to tell if yours is genuine

Counterfeits of Mexican 8 Reales exist, including cast fakes and modern struck copies. Three quick checks:

1. Weigh it. A genuine coin is 27.07 grams. Use a jewelry scale. A fake often comes in light or heavy.
2. Measure it. Diameter should be 39 mm. Use calipers.
3. Read the edge and details. The edge is reeded, not smooth. Look at the sharpness of the engraving, the Pi mint mark, and the assayer initials. Cast fakes look soft and mushy.

Be suspicious of any deal priced far below the silver value. If you want certainty, submit it to a grading service like NGC or PCGS, which authenticates and grades in one step.

Where to sell it

• A verified numismatic dealer from the Pesoteca shop directory will value it on the spot and pay fair market, without a middleman markup.
• The Pesoteca buy-and-sell forum connects you directly with collectors.
• For anything you suspect is high grade or a scarce variety, get it certified first. A slabbed MS coin sells for far more than a raw one.

Before selling, photograph the obverse, reverse, and edge in good light, and confirm the grade against our coin grading guide. Do not dump it to the first buyer on social media.

This coin belongs to the Mexican Republic 8 Reales silver series, where date and mint drive most of the price spread.

Got an 1887 San Luis Potosí 8 Reales in hand and not sure of the grade? Post clear photos of both sides on the Pesoteca forum and let the community help you pin down what it's really worth.

In 1887, Porfirio Díaz governed in his second continuous term. Years of railroad expansion (Mexico City-Ciudad Juárez, Mexico City-Laredo) and of consolidation of foreign capital in mining and industry.

The San Luis Potosí mint (Pi) operated from 1827, fed by the mines of Cerro Potosí and Real de Catorce. It closed in 1893 in the centralizing reform of the mid-Porfiriato.

Pi pieces have strong regional demand. Late years (1892-1893) are less common because of the mint's imminent closure.

In catalog reference, the variant of this mint is listed as KM#377.12 in Krause. The piece is .9028 fineness silver with a reeded edge and a theoretical weight of 27.07 grams. The 1887 San Luis Potosí example corresponds to the mature phase of the mint, near its closure (1827-1893), and is identified on the coin by the mint mark Pi.

When hunting radiant-cap 8 reales from Pi, it's worth comparing against the photographic reference in the Pesoteca catalog and prioritizing examples with a legible reverse (eagle, serpent, legend REPÚBLICA MEXICANA, and value 8R) over pieces with only a bright obverse. The peer-to-peer price among collectors of the 1880s cycle tends to be fairer than the display case of a specialized shop, where the dealer markup can double the real reference.