Short answer
A replica Rolex gold watch is a copy that mimics an 18k gold Rolex, most often a Day-Date, Datejust, or Submariner. The case is steel, brass, or tungsten with a gold color film. Gold content is zero in most units. Plating thickness runs 0.5 to 5 microns. One micron is 0.001 mm.
Gold content and mass
Rolex casts its gold cases in 18k alloy: 750 parts gold per 1000. Density of 18k gold is about 15.5 g/cm3. Steel is 7.9. Brass is 8.5. Tungsten is 19.3.
A gold Day-Date 40 on a full bracelet weighs about 200 g. A steel copy of the same model weighs 130 g to 150 g. Some sellers add a tungsten core to reach 200 g. Tungsten is denser than gold, so a scale alone cannot separate the two.
Coating types
- Electroplating: 0.5 to 3 microns. Wear shows first at the crown, clasp, and caseback.
- PVD and TiN: titanium nitride film, hardness about 2000 HV. Color matches gold. No gold in the film.
- Gold filled: 5 to 10 microns bonded to base metal. Few replica sellers use it.
- Solid 18k copy: a workshop casts the case in real gold and fits a clone movement. Price tracks the gold spot price.
Tests
XRF reads the top 1 to 10 microns. A plated case can read 18k on the surface.
Specific gravity: weigh the watch dry, weigh it submerged, divide the two numbers. 18k gold lands at 15.2 to 16.0. Steel lands at 7.8 to 8.0.
Acid test: file a cut in an inner surface, apply nitric acid, read the color. The test destroys the finish.
Hallmarks: Swiss gold carries the St. Bernard dog head control mark. Rolex stamps 750 on the case between the lugs. Copy stamps exist, so a stamp is not proof.
Movement and other marks
Rolex cal. 3235 runs at 28,800 vph with a 70 hour power reserve. Common clone calibers are SA3135, VR3135, and SA3235. Many run at 28,800 vph. Beat rate alone does not identify a movement.
Other checks: cyclops magnification at 2.5x, date font, crown shape, and the fit between the case and the end links.
US law
18 U.S.C. 2320 covers trafficking in counterfeit goods. A first offense carries up to 10 years and a $2 million fine for an individual. A second offense carries up to 20 years and a $5 million fine.
19 U.S.C. 1526 lets Customs seize and destroy counterfeit imports. The buyer faces loss of the goods and a civil penalty.
15 U.S.C. 291 to 300, the Gold and Silver Stamping Act, requires an accurate quality mark on gold articles sold in the US. A plated watch stamped 750 breaks that rule.
Service and resale
Rolex service centers do not service counterfeits. Independent watchmakers may refuse as well. Plating wear is not repairable at low cost against the price of the watch. Resale value after plating wear is close to zero.
Checks before a purchase
- Ask for the weight in grams on a scale photo.
- Ask for a specific gravity result, not a magnet test.
- Ask for an XRF reading on a filed inner surface.
- Ask for the movement caliber and a photo of the balance wheel.