Answer first
A fake Blancpain moon phase fails on three checks: the moon disc, the calendar correctors, and the movement. Genuine Villeret Quantieme Complet watches run an in-house Blancpain caliber with a complete calendar and a moon aperture at 6 o'clock. Copies use commodity movements with an added moon module. Dial photos catch the common fakes. A movement photo, taken with the caseback open, settles the question.
What the genuine watch does
Blancpain builds the Quantieme Complet in the Villeret line. The dial carries day and month windows below 12 o'clock, a date pointer, and the moon phase at 6 o'clock. The moon disc turns behind an aperture. Blancpain fits a corrector pusher in the case band for each calendar function. The pushers sit recessed in the case and need a stylus to press.
A standard moon phase train uses a 59-tooth wheel driven one tooth per day. That gives a 29.5-day cycle. The synodic month is 29.53059 days, so the display drifts about one day every 32 months. The owner resets it with the corrector, not with the crown.
Check 1: the moon disc
- Moon face: genuine discs show a raised moon with a face and surface detail. Copies print a flat circle.
- Stars: genuine stars vary in size and sit in polished relief. Copies use a uniform dot pattern.
- Aperture edge: genuine apertures are beveled and polished. Copies show a stamped edge and an uneven gap.
- Color: genuine moon discs use a deep blue background. Copies look purple or black under strong light.
Check 2: day and month windows
- Typeface: check the font weight against a catalog photo. Copies use a heavier, wider numeral.
- Alignment: both windows sit on the same horizontal line. Copies sit a fraction low or high.
- Disc edges: genuine windows show a clean, dark gap around the disc. Copies show white edges or glue marks.
Check 3: the movement
Genuine Villeret complete calendar watches use Blancpain caliber 6654 or a close variant. The 6654 is an in-house automatic with a full calendar module. Copies use third-party automatics with a bolted-on moon plate, or quartz. Ask for a photo through the caseback. Look for the caliber engraving, Geneva stripes on the bridges, and a decorated rotor. A fake shows a printed logo on a plain rotor and no anglage on the bridges.
Check 4: case and markings
Steel Villeret cases measure about 40 mm across. The reference number sits between the lugs, and the engraving is crisp and deep. Copies show shallow laser text and a serial that does not match the papers. On two-tone copies, gold plating wears at the lugs and crown. Caseback text on copies is thin, and the sapphire is often mineral glass. A gold case also carries far more weight than a plated copy.
Check 5: price and paperwork
Copies sell for about $200 to $900, with better movements at the top of that range. Genuine Villeret Quantieme Complet list prices sit above $10,000. A new moon phase watch under $1,000 is a copy. Ask for the box, the warranty card, and service records. A seller who cannot name the caliber is not selling a genuine watch.
What photos cannot prove
A good copy passes a dial check at arm's length. Only a watchmaker with the caseback open can confirm the caliber, the calendar module, and the moon wheel ratio. Ask for a timed accuracy reading and a service invoice before you pay.