The Jaeger-LeCoultre Master Calendar ref. Q1558421 is among the most visually arresting executions of the Master line's annual-calendar complication, distinguished by a genuine meteorite dial that makes every example one of a kind. The Widmanstätten crystal structure — formed over billions of years — spreads across the silver-grey surface in bold, intersecting bands, a pattern no two dials share. Against that cosmic backdrop, black Arabic numerals ring the outer date track, with the 31 rendered in blue as a quick visual cue for month-end. A day window and a month window sit symmetrically just above centre, their white apertures reading WED and JUL in the photos. The 3 o'clock numeral is accompanied by a blue crescent moon-phase indicator, and a sub-dial at 6 o'clock houses the full moon-phase display — a blue enamel-style hemisphere dotted with gold stars and a gilt moon, ringed by a seconds track marked AUTOMATIC and SWISS MADE. Faceted sword hands in a steel-grey finish carry across the dial without competing with the meteorite texture beneath them. The polished stainless steel case wears a clean, dressy profile with gently curved lugs and a plain polished bezel. The exhibition caseback reveals the automatic movement, its gold-toned rotor and côtes-de-Genève-finished bridges visible through the sapphire glass; the engraved surround reads Jaeger-LeCoultre. The watch is presented on a black alligator-pattern strap with a deployant clasp. Excellent condition with Jaeger-LeCoultre box, Guarantee Certificate dated 2017-7-25, and an unworn JLC black strap.