Decimal issues of the Alamos mint

Copper

One centavo 

Diameter 25 mm. 

KM-391 1c 1880 As (Ponterio Baltimore auction, 28 March 2011, lot 8808)

Silver

Five centavos

Diameter 15 mm. 1.353 g. 0.9027 silver 

KM-398 5c 1874 As DL (Stack’s- Bowers Kirk Menczer Collection, October 21 2025, lot 71063)

KM-398 5c 1878 As L mule (Stack’s Bowers Kirk Menczer Collection, 21 October 2025, lot 71066)

Ten centavos 

Diameter 17 mm. 2.707 g. 0.9027 silver 

KM-403 10c 1884 As L (Stack’s- Bowers Kirk Menczer Collection, October 21 2025, lot 71236)

Twenty-five centavos

Diameter 25 mm. 6.768 g. 0.9027 silver 

KM-406 25c 1883 A L (Stack’s Bowers Kirk Menczer Collection, 22 October 2025, lot 72039)

Fifty centavos

Diameter 30 mm.13.536 g. 0.9027 silver 

KM-407 50c 1888 As L (Ponterio Baltimore auction, 28 March 2011, lot 9142)

Gold

One peso

Diameter 15 mm.1.692 g. 0.8750 gold 

KM-410 $1 1888 AsL/M (Stack’s-Bowers NYINC auction, 12 January 2019, lot 41221)

The only gold Peso issue from the Alamos mint. It is evident that the entire engraving was re-engraved on a Mexico City peso die. Close inspection reveals remnants of an M beneath the L assayer letter as well as the faint shadow of a bar below the s in the As mintmark where an Mo mintmark once existed. 

2½ pesos 

Diameter 18 mm. 4.230 g. 0.8750 gold 

KM-411 $2½ 1888 As/MoL (Briggs & Bustos auction VIII, April 2024, lot 381)

In the description Briggs & Bustos state: "One of the many rarities for this year, this unusual and rare denomination by itself was struck only in 1888 at the Alamos mint, with a mintage that remains unknown. As is the case with some other mints, it is interesting that all of these specimens were struck with a reverse engraved in the As/Mo mintmark, with no trace of an assayer over-assayer. Although there is no documentation, one theory is that they may have been prepared as part of a "presentation" cone ordered by the Mexican mint, for which dies were sent from the capital to various mints in order to complete the cone for this date. The truth is that this piece is much rarer than the 1 peso gold coins of the same date and mint that also present the As/Mo re-engraving in mint, we did not locate public records at auction for this type in the last three decades."

Five pesos 

Diameter 22 mm. 8.460 g. 0.8750 gold 

KM-412 $5 1878 As L (Heritage auction, 26 May 2016, lot 64275) 

Ten pesos 

Diameter 27 mm. 16.920 g. 0.8750 gold 

KM-413 $10 1890 As L (Stack’s-Bowers auction, 17 October 2018, lot 72667)

KM-413 $10 1894/3 As L (Stack’s-Bowers NYINC auction, January 2014, January 2014, lot 1393)

Twenty pesos

Diameter 34 mm. 33.840 g. 0.8750 gold