The Rolex Day-Date ref. 18238 from 1991 is a classic expression of Rolex’s flagship dress watch, featuring a 36 mm case crafted entirely from 18k yellow gold, the iconic fluted bezel and President bracelet. It is powered by the automatic calibre 3155, which introduced the practical double quick-set function for independently adjusting both the day and date. What makes this particular configuration especially distinctive is its natural malachite stone dial. Each malachite dial displays its own unique layers and patterns of rich green, meaning no two examples are exactly alike. Rolex produced stone-dial Day-Dates in far smaller quantities than models with conventional dials, and surviving examples with original malachite dials are particularly uncommon. The combination of yellow gold, the characteristic green natural stone and the unmistakable President design makes the 18238 Malachite one of the more distinctive and collectible configurations from this generation of the Day-Date.