Arnold & Son / HM Pietersite
Key Highlights
- Ultra-thin 39.5 mm dress watch in 18-carat red gold or stainless steel, only 7.82 mm thick.
- Namibian pietersite dial, the “stone of storms”, with swirling, storm-like patterns.
- In-house manual-winding calibre A&S1001, 2.70 mm thick with a 90-hour power reserve.
- Limited to 8 pieces in red gold and 18 in steel, with exhibition case back and 30 m water resistance.
- Ink blue alligator strap echoing the dial’s deep blue tones.
The Stone of Storms
The HM Pietersite centres on a dial cut from pietersite, a decorative mineral and variety of chalcedony discovered in Namibia in the early 1960s by Sid Pieters. Known as the “stone of storms”, it shows swirling patterns that suggest movement within the stone.
On this model, the stone evokes Cornwall under rough weather, with skies and waves breaking against a rugged coastline linked to John Arnold’s work on precision timekeeping for navigation. Each pietersite dial is naturally unique, with deep blue tones mirrored by the ink blue strap.
A Tribute to John Arnold and Marine Chronometry
The HM Pietersite sits within the history of navigation. In 1714, the British Parliament offered a reward to anyone able to determine longitude at sea; John Harrison showed that a timekeeper could solve the problem, and John Arnold later enabled broader use of this breakthrough through precise, serially produced marine chronometers.
The HM designation nods to this maritime heritage. It indicates a display restricted to hours and minutes, while recalling Royal Navy naming conventions where HM stood for His or Her Majesty’s and later HMS for His/Her Majesty’s Ship.
Ultra-Thin Elegance and Proportions
The case measures 39.5 mm in diameter and 7.82 mm in thickness, placing the HM Pietersite among ultra-thin dress watches. Offered in 18-carat red gold (5N) or stainless steel, it wears discreetly while leaving visual space for the stone dial.
The display is restrained, with only hours and minutes, so the pietersite can be read almost like a maritime painting. A domed sapphire crystal with double-sided anti-reflective coating covers the dial, and a sapphire case back with similar treatment reveals the movement. Water resistance is 3 bar (30 metres or 100 feet), and a pin buckle in red gold or steel matches the case and secures the ink blue alligator strap.
The A&S1001 Calibre
The HM Pietersite is powered by the in-house calibre A&S1001, a mechanical manual-winding movement from Arnold & Son’s family of dress-watch calibres. It measures 30 mm in diameter and only 2.70 mm in height, supporting the watch’s ultra-thin profile, and delivers a 90-hour power reserve from a single barrel.
The regulating organ beats at 21,600 vibrations per hour (3 Hz). Through the transparent case back, the finishing includes a rhodium-plated main plate with circular graining, chamfered bridges with radiating Côtes de Genève, snail-finished wheels and blued screws with polished, chamfered heads.
Edition, Materials and Specifications
Arnold & Son has chosen tightly limited production for the HM Pietersite. The red gold reference 1LCDR.Z01A.C1506A is limited to 8 pieces, while the stainless steel reference 1LCDS.Z02A.C1506S is limited to 18 pieces, both sharing the pietersite dial, A&S1001 calibre, sapphire crystals and 30-metre water resistance.
The dial is described as Namibian pietersite, underlining the stone’s origin. Case material in 18-carat red gold (5N) or stainless steel is matched to the pin buckle, while both versions are fitted with an ink blue alligator leather strap positioned for dress-watch use.
Why It Matters
For GCC collectors, the HM Pietersite combines narrative, craftsmanship and rarity. Its ultra-thin profile, limited production in red gold and steel, and 90-hour power reserve are paired with a pietersite dial that speaks to sea, storms and exploration at the heart of Arnold & Son’s history. It stands out as a discreet dress piece with clear historical and aesthetic context.
For curated access to limited editions and pietersite-dial creations in the region, speak with your preferred boutique or register your interest with our editorial team to stay informed about Arnold & Son highlights tailored to GCC collectors.
