How to Identify the French Half Ecu (Demi-Ecu)
Confirm a constitutional demi-ecu of Louis XVI by its left-facing royal bust, winged-genius reverse, L'AN 4 DE LA LIBERTE legend, and 1792 date.
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Start with the two designs together. The defining combination is a left-facing bust of Louis XVI on the obverse and a standing winged genius engraving an altar on the reverse. Neither side alone is enough; it is the pairing, plus the revolutionary legend, that marks this constitutional type.
Read the revolutionary legend and date. Look for L'AN 4 DE LA LIBERTE and the year 1792. The 'Year of Liberty' wording is diagnostic of the constitutional monarchy coinage and separates these pieces from earlier, purely royal ecus that carry only Latin titles and a crowned-arms reverse.
Check size, metal, and mint marks. The demi-ecu is a large, heavy silver coin (roughly half-crown scale, and about half the mass of the full ecu). It should be non-magnetic with a clear silver ring. Scan the legends for a single mint letter and tiny privy or engraver marks; these identify the striking mint and are expected on genuine coins.
Separate half ecu from full ecu. The full ecu and demi-ecu share the same designs, so do not judge by imagery alone. Weigh and measure the coin: the demi-ecu is distinctly smaller and lighter. A large 'genie' coin at full-ecu weight is the ecu, not the half.
Authenticate with care. Toning like the iridescence on this example can be genuine, but it can also be simulated. Watch for cast surfaces, soft or mushy relief, wrong weight or diameter, seams on the edge, and dates or mint marks that do not match known combinations. For valuable pieces, rely on third-party grading or a specialist in French Revolution coinage.
Frequently asked questions
How do I tell a demi-ecu from a full ecu?
They share the same designs, so use weight and diameter. The demi-ecu is noticeably smaller and about half the mass of the full ecu; confirm with a scale and calipers rather than by design alone.
How is this different from an older royal ecu?
Pre-Revolution ecus show a crowned coat-of-arms reverse and Latin royal titles. This constitutional issue instead has the winged-genius reverse and the French legend L'AN 4 DE LA LIBERTE with an 1792 date.
Where is the mint mark?
French coins of this era carry a mint letter and small privy marks worked into the legends. Locate the letter to identify the striking mint; missing or nonsensical marks are a warning sign.
What are the fastest authenticity checks?
Verify silver (non-magnetic, correct weight and diameter, ringing tone), sharp period relief on both bust and genius, and a matching 1792 date with mint mark. Send high-value coins for professional authentication.