This coin was produced under Juan Gutiérrez, the first assayer of the late series who introduced the type. His appointment spanned two periods 1542-43 and again 1544-1546. Recovered from the “Golden Fleece” shipwreck sunk circa 1550 with all Mexican coins predating Rodrigo Gómez de Santillán (Assayer S), who began his appointment in 1553.
Reference article: https://www.sedwickcoins.com/articles/carlosyjuana.pdf
Mexico City, Mexico, 4 reales, Charles-Joanna, “Late Series,” assayer G to right, mintmark M to left (M-G), NGC AU 55 / Golden Fleece (Shipwreck Blue Label). Nesmith-50e type; Cal-127; S-M5; KM-18. 13.35 grams. Very broad flan that extends past the 100% full legends, also choice full inner details, deeply toned but without any corrosion at all. Recovered from: “Golden Fleece wreck,” sunk ca. 1550 in the Northern Caribbean.
Please use this link to verify the certification number: https://www.ngccoin.com/certlookup/6531548-001/55/
