Obverse: identify the front

The normal the reference types describe a facing eagle with a snake in its beak. REPUBLICA MEXICANA identifies the republic around the national emblem. Eagle details can vary between dies and mints; a familiar Mexican emblem alone does not identify metal, denomination or the correct historical standard. Keep the full rim, legends and the opposite face available when comparing a specimen with a catalogued issue.

Reverse: identify the back

The cap/scales type carries a radiant liberty cap above scales, with further law-and-sword detail and the 20-peso wording. Record the actual mint and assayer characters as well as the .875 fineness marking where visible. The smaller historical one- and two-and-a-half-peso gold value reverses differ. A denomination or eagle image alone does not distinguish this large historical standard from later .900 gold pesos.

History and purpose

Mexico’s decimal Second Republic gold coinage included several peso denominations and regional mint/assayer combinations. This guide groups matching normal metal standards while preserving each dated mint variety for identification. Later .900 gold pesos and modern bullion belong to different coin families. A denomination reused in another period is not evidence that the same historical gold-content calculation applies.

How to identify this variant

Confirm the Second Republic gold type, 20-peso denomination, national eagle, cap/scales reverse, full date and mint/assayer combination. The reference reports 33.84 g gross and .875 gold. Physical diameter and edge still require a matching reference; no universal dimension is guessed. A later same-denomination coin is not assigned this heavier historical gold standard solely because its peso amount matches.

Understanding its metal content

The reference reports .9519 reference fine gold troy ounce per matching normal coin. Three pieces total 2.8557 reference fine ounces and 101.52 nominal gross grams. Gross mass times .875 gives 29.61000 fine grams per coin, approximately 0.951984 troy ounce. This arithmetic is disclosed separately from the rounded designated AGW. Unspecified alloy remainder is not additional gold, and a worn specimen requires individual assessment.

Dates, varieties and composition changes

Accepted actual engraved years are 1870–1905. The detailed annual union includes every 1870–1905year. The 1876MoM combination is reported but unconfirmed and is excluded as a proven variety; other 1876 mint rows independently establish the family year. Chihuahua uses CH or Ca in different entries, and the normal family includes several other regional mint types. Retain complete overdates and mint/assayer attributions without inventing a scarcity grade, die-error identity or premium.

Melt value versus collector value

A dated regional mint issue, overdate or die combination may need individual numismatic appraisal before a metal-content sale. Preservation, cleaning, mounting and retained certification affect that assessment. This guide assigns no grade, scarcity claim, current catalog price or expected premium. Keep each coin’s full attribution and original surfaces intact instead of treating an unexamined historical lot solely as scrap.

Authenticity and condition

Photographs, yellow color and a scale reading cannot authenticate a coin by themselves. Document the complete faces, rim and edge without cleaning, acid testing or scraping. Confirm the catalogued date/mint combination and obtain the missing physical reference dimensions where needed. Exclude uncertain pieces, altered denominations and unidentified replicas from a confirmed nominal collection total until examined.

Selling this coin

Separate these .875 Second Republic gold issues from later .900 pesos, silver pesos and modern bullion. Supply dated mint/assayer notes, full-rim both-side photographs and any original certification through the existing CashForCoins appraisal process. A nominal fine-gold quantity helps describe a lot; it is not a guaranteed offer. Missing market-provider data must remain unavailable rather than displaying a zero-dollar melt value.

Sources and calculation methodology

The reference designated World Gold retains 33.84 g/.875/.9519 reference AGW for normal historical 20 pesos. Detailed Numista dated catalog rows establish the accepted annual union 1870–1905; market prices and mintages are excluded. The 1876MoM row is explicitly reported/unconfirmed and is excluded as an established combination; other 1876 mint entries establish that family year. The reference KM 414 corroborates the metal standard and cap/scales design. Neither a universal diameter nor thickness is established by the inspected matching records. No dimension or photographic permission is invented. Metal inputs remain from the user-designated reference table rather than another catalog’s substitute. Actual dated rows are distinct from an envelope of possible years, and unconfirmed entries do not establish varieties.

The designated melt table reports .9519 AGW; a differently rounded dated reference reports .9520. The calculation follows .9519 directly. These printed precision differences do not establish separate gold alloys or weights.

Common questions

References

• NGC designated World Gold historical metal specification — normal 20-peso identity; 33.84 g gross; .875; .9520 reference AGW (checked 2026-10-12)
• Detailed dated catalog: normal Second Republic gold 20 pesos — actual annual row union; mint/assayer and cap/scales design; reported/unconfirmed combinations excluded; no prices/mintage or images copied (checked 2026-10-12)
• NGC matching normal twenty-peso KM414 — 33.8400g;.875;.952AGW;facing eagle and radiant cap/scales;selected1888AsL rare (checked 2026-10-12)
• Banco de México exact photographed 1880 specimen, inventory4971 — identity; design; dates; measured specimen weight and diameter, distinct from retained nominal standards; source-specific paired institutional photographs (checked 2026-10-12)
• NGC exact dated catalogue match to photographed historical Mexican gold type — identity; design; dates; weight; fineness; photographed1880 Mexico City type and assay characters (checked 2026-10-12)

Issue-year references

• NGC designated World Gold historical metal specification
• Detailed dated catalog: normal Second Republic gold 20 pesos
• NGC matching normal twenty-peso KM414

Content maintained by CashForCoins. Last substantive record update: 2026-10-12. Report a specification or attribution issue through our contact page.

Related coins

Mexico 20 peso Azteca gold

Photo credits and rights on the linked coin profile.

Mexico • 90% gold; balance alloy metal

Issue years: 1917–1921, 1959

Fine gold: 0.482200 troy oz

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