How to Identify the 30 Sols (Half Ecu)

Begin with the obverse legend, because it does most of the work. The constitutional 30 sols shows Louis XVI in profile encircled by 'LOUIS XVI ROI DES FRANCAIS.' The phrase 'Roi des Francais'—King of the French—is diagnostic: earlier royal coins read 'Roi de France (et de Navarre).' If the legend names the king as ruler of the French rather than of France, you are looking at a Revolutionary-era issue.

Turn to the reverse to confirm the type. Look for a standing figure of Liberty holding a flag and a shield, surrounded by the legend 'L'AN 4 DE LA LIBERTE,' with the date 1791. This pairing of a Liberty allegory and a 'year of Liberty' date—rather than a crowned royal shield—separates the constitutional coinage from the older monarchy's silver.

Use size and metal as a cross-check. The 30 sols is a silver coin of middling size, larger than the small silver sols pieces but smaller and lighter than the full silver ecu. Weigh and measure a candidate against published specifications for the 1791 30 sols; a coin that is markedly too heavy, too light, or base-metal in color should be treated with suspicion.

Watch for look-alikes and alterations. Louis XVI appears on several silver denominations, so do not judge by the portrait alone—read both legends and the denomination together. Be alert to cast copies with soft, mushy detail or seams on the edge, to harshly cleaned surfaces, and to added or repaired areas around the date, which is a prime spot for tampering on historically charged coins.

When authenticity affects value, corroborate before you buy. Compare against trusted reference images of the 1791 constitutional 30 sols, check the edge and rims for filing or mounting, and for higher-value examples consider third-party grading. The strongest single confirmation remains the 'Roi des Francais' obverse combined with the Liberty reverse dated 'L'An 4 de la Liberte.'