The steel Lady-Datejust with a blue diamond dial.

The Lady-Datejust is the Datejust at 26mm, the size Rolex made for women from the 1950s until it moved the line to 28mm in 2015. It is the same watch in miniature: an Oyster case with a screw-down crown, an automatic chronometer movement, the date under its Cyclops lens at three, a fluted or engine-turned bezel, and a Jubilee or Oyster bracelet. Because Rolex made them for six decades in every dial and metal, the pre-owned market is deep and this is where the money goes when people search for a women’s Rolex.

The blue diamond dial is the way to have a jewelled Lady-Datejust without any yellow gold: the bezel is white gold, the case and Jubilee are steel, and the ten diamonds sit on a sunburst blue that goes from navy to bright depending on the light. Rebag does not give a reference; a steel 26mm Lady-Datejust with a fluted white gold bezel on a Jubilee is the 179174 in the 2000s and the 79174 in the 1990s, and the dated card will say which.

Rebag gives the case at 26mm and 11mm high, the band at 13mm, a wrist size of about 6 inches, the band and case as steel, the dial colour as blue, an automatic movement with date and a screw-down crown, the condition as Very Good with scratches and minor wear on the case and band, and a dated warranty card as included. It gives no reference. The white gold bezel and diamond markers are in the listing title and the photograph; the chronometer rating, reserve and 100 metres are Rolex’s published figures.

Rebag authenticates in-house and is not a Rolex authorised dealer, and Amazon adds its 30-day return window. Ask for the reference and the date on the card, whether the box is included, and when it was last serviced. Nothing here was measured on the watch.

This unit is sold by Rebag through Amazon Luxury Stores, authenticated by the seller with Amazon’s 30-day return window on top; it is one piece, and when it sells the listing goes away, so the second button opens the live search for 26mm Lady-Datejusts.

Steel and two-tone Lady-Datejusts have resold close to what pre-owned buyers paid, sometimes more, sometimes less; that is a pattern, not a promise, and nothing here is investment advice.