The HM Perpetual Moon Aventurine offers a spectacular solid gold moon phase beautifully harmonising with a sparkling blue aventurine quartz dial and paired with an in-house Arnold & Son mechanical calibre.

Demonstrating its British history and Swiss savoir-faire, Arnold & Son presents the HM Perpetual Moon with a blue aventurine quartz dial, preserving the House’s expertise in astronomical complications.

The timepiece houses the exclusive Arnold & Son mechanical hand-wound calibre A&S1512 exclusively developed for the moon phases complication and equipped with a double barrel to yield a 90-hour power reserve. This movement supply a precision moon phase with one day deviation every 122 years and offers a unique easy-to-set feature thanks to the addition of a second moon phases indicator visible through the transparent case back.


Beyond technological aspects of the HM Perpetual Moon Aventurine, the entire rhodium plated movement features hand finishing including: chamfered with polished edges, Côtes de Genève and fine circular grained bridges, circular grained wheels, blued screws with polished and chamfered edges.
In addition, the moon phase guilloché disc, running from 10 o’clock to 2 o’clock, reveals a solid 18-karat red gold engraved moon. Faceted hours and minutes hands run along twelve golden indexes applied on the blue aventurine quartz dial.

The 42 mm diameter, 18-karat red gold case is sealed with an antireflection sapphire crystal and adorned with a hand-stitched alligator strap, fastened with an 18-karat red gold pin buckle.

HM Perpetual Moon Aventurine – Technical specifications

Functions Hours, minutes, precision moon phase indicator, second moon phase indicator case back
Calibre A&S1512, mechanical hand-wound
Jewels 27
Diameter 34 mm
Height 5.35 mm
Power reserve 90 hours
Frequency 3 Hz / 21,600 vph
Decoration Rhodium plated Haute Horlogerie finishing: hand chamfered bridges with polished edges, circular graining and sunray Côtes de Genève, blued screws with polished and chamfered edges
Dial Blue aventurine quartz, blue lacquered guilloché moon disc, solid 18-karat red gold (5N) moon and golden stars
Back: fine circular graining, rhodium plated, moon phase indicator
Material 18-karat red gold (5N)
Diameter 42 mm
Thickness 11.43 mm
Crystal Cambered sapphire, antireflection coating on both sides
Back Sapphire crystal
Water resistance 30 m /100 ft
Strap Material Hand-stitched brown alligator leather
Buckle Pin, 18-karat red gold (5N)
Reference number 1GLAR.A01A.C123A
Limited edition 28 pieces
World retail price CHF 31’900 (prices can be subject to change)