How to Identify the Spanish Doubloon (8 Escudos)

Start with size and metal. The 8 Escudos is a large gold coin, roughly 34-37 mm in diameter and near an ounce in weight, with the deep yellow color of high-fineness gold. If your piece is noticeably smaller or lighter, it may be a lower escudo denomination (4, 2, or 1 escudos) sharing similar designs, or a modern reproduction.

Read the obverse. You should see a draped, armored bust of a king facing right, ringed by a Latin legend naming Carlos IV (Charles IV) with his titles. Confirm the date falls within his reign of 1788-1808; the pictured coin reads 1798. A bust facing the opposite way, or a different name in the legend, points to a different ruler such as Charles III or Ferdinand VII.

Check the reverse. Look for the crowned Spanish coat of arms with a cross, typically surrounded by the linked collar of the Order of the Golden Fleece. Within the legends, locate the mint mark and the assayer's initials, plus the "8" denomination mark; these identify where and by whom the coin was struck. Spain and several American mints each used their own marks.

Distinguish look-alikes. Lower escudo denominations use nearly identical designs at smaller sizes, so verify the denomination mark and measure carefully. Coins of Charles III (to 1788) and Ferdinand VII (from 1808) carry different busts and names, and later Spanish-American republican gold drops the king entirely. Do not confuse the term "doubloon" with the smaller 2 escudos, which some sources also called a doubloon historically.

Authenticate with caution. Gold coins of this type have been widely counterfeited, from period fakes to modern cast and struck copies and gold-plated base-metal pieces. Weigh and measure the coin precisely, inspect the edge and fields for casting seams or a dull, soapy surface, and be wary of coins that feel too light. When value is significant, seek third-party grading or an experienced dealer before buying or selling.