The short answer

On nearly every Ladybird listing, the stones are cubic zirconia. Sometimes they are moissanite. Almost never are they real diamonds, and when a seller insists they are, treat that as your cue to walk. A diamond bezel of the size used on a 26 mm ladies' watch holds dozens of tiny stones, and setting them by hand costs more than a first copy case and bracelet combined. If the price looks like a first copy price, the stones are simulants.

The name itself is loose. Ladybird gets attached to small vintage-style ladies' dress watches, and in the replica trade it now labels almost any 26 to 31 mm diamond-set ladies' watch, most often one shaped like the Lady-Datejust. So when you search that phrase, you are shopping a look, not a single reference number.

What the stones actually are

• Cubic zirconia: The default. Hardness around 8 to 8.5 on the Mohs scale, so it scratches and dulls with wear. Cheap, bright, and slightly warmer in color than diamond under daylight. On a watch bezel it looks fine for a year or two of daily wear, then starts going cloudy at the edges.
• Moissanite: Hardness around 9.25, close enough to diamond that it stays crisp for years. It throws more rainbow fire than diamond, which some people love and some find obvious next to the real thing. Costs more than CZ, still far below diamond.
• Lab-grown diamond: Chemically the same as mined diamond. Rarely used on first copy watches because the stones alone would double the price, but a few sellers offer it as an upgrade.
• Natural diamond: Essentially never on a first copy. If it were, you would be paying thousands, and the seller would have paperwork.

The FTC jewelry guides require that simulants be disclosed and never simply called diamonds. A listing that says diamond with no qualifier and no certificate is either sloppy or dishonest. Either way, assume CZ.

Where replicas give themselves away

Stones are only part of it. I look at the setting first, because that is where cheap work shows. Real diamond bezels are prong or channel set, with each stone held by metal. Budget replicas often glue stones into a drilled bezel, and glued stones fall out, usually within months, and usually in a spot you will not notice until you are at dinner.

• Alignment: Run a fingertip along the bezel. Stones should sit at even height. A wavy line reads as fake from arm's length.
• Color match: All stones should be the same shade. Mixed tones mean mixed batches.
• Case size: Genuine ladies' references sit at 26, 28, or 31 mm. A Ladybird listed at 36 mm is a men's case with a diamond bezel.
• Weight and bracelet: Jubilee bracelets should articulate smoothly and feel dense. Light, rattly links are the giveaway most people notice without knowing why.
• Movement: Many ladies' first copies run quartz. That is not a defect, it is part of the price. Ask which movement you are buying.
• Water resistance: Never trust a depth rating on a replica. ISO 22810 exists so ratings mean something testable, and a copy has not been tested to it. Take the watch off before you wash your hands.

What each price tier buys

Below roughly $150, expect CZ in a glued or poorly pronged bezel, a plated case, and a quartz movement. Between $150 and $400, you get a proper prong setting, better plating, sharper dial printing, and often a nicer bracelet. Above that, you are paying for case finishing, movement quality, and stone grade, and at that point moissanite becomes realistic. Past a certain number, stop and ask why you are not buying a used genuine ladies' watch instead.

Care and honest expectations

Treat a CZ bezel like costume jewelry with a movement. Wipe it with a soft cloth after wear. Keep perfume, hairspray, and sunscreen off the stones, since residue dulls them fast. Skip the ultrasonic cleaner unless you know the stones are prong set, because it can shake loose glued ones. Check the bezel every few months with a bright light and a fingernail.

A first copy ladies' watch with a diamond-style bezel is a look, and it does that job well. It is not an investment and it is not a diamond watch. Buy it knowing which one you are getting, and you will enjoy it a lot more.