Sugess V3 Moonphase Watch — Blue Sandstone Dial, ST2528, Big Date, 41mm

Sugess V3 Moonphase Watch — Blue Sandstone Dial, ST2528, Big Date, 41mm

The Sugess V3 Moonphase (model S437) is a 41mm automatic watch powered by the Seagull ST2528 — a high-beat caliber at 28,800 vph — presenting two simultaneous complications: a luminous moonphase display and a big date window. The dial is crafted from blue sandstone, a deep blue mineral-glass material with metallic fleck inclusions that create a shifting sparkle effect. BGW9 Super-LumiNova on the moonphase disc and hands. Sapphire crystal, 50m water resistance. Available in blue leather, black leather or stainless steel bracelet options across the V3 and S437 configurations.

Key Specifications

Variants — Ten Configurations

V3 Edition (Blue Sandstone Dial)

Black strap V3: Blue sandstone dial on black leather strap. Blue strap V3: Blue sandstone dial on blue leather strap — the most tonally cohesive configuration, with the strap matching the dial’s deep blue character. SS bracelet V3: Blue sandstone dial on stainless steel bracelet — the most formal and substantial configuration at the highest wearing weight.

S437 Series (Multiple Dial Options)

S437 RG Blue / SS Blue / SS Black / RG Black / RG White / SS White: The S437 series offers the same moonphase and big date architecture across rose gold (RG) and silver steel (SS) case hardware in blue, black and white dial options. These variants use standard dial materials rather than sandstone.

Blue Sandstone Dial

Blue sandstone — sometimes also called blue goldstone — is a manufactured mineral-glass material, not a naturally occurring stone. It is produced by fusing glass with metallic compounds (typically cobalt or copper) under controlled conditions, suspending bright metallic particles throughout the glass matrix. The effect is a deep blue field filled with bright, randomly distributed metallic flecks that catch and refract ambient light.

The appearance shifts continuously as the wrist angle changes — individual flecks brighten and dim as they face toward or away from the light source, creating the characteristic star-field visual effect. Each dial panel is unique in the distribution of its fleck pattern.

On a moonphase watch, the blue sandstone dial creates a visual environment that frames the moonphase complication’s own celestial character — deep blue field with bright points, complementing the moon disc above a starry background at 6 o’clock.

Seagull ST2528 — Moonphase Accuracy

The ST2528 tracks the lunar cycle at an accuracy of approximately 57 seconds per 29.5-day cycle — equivalent to less than 2 seconds per day of drift. Most mechanical moonphase movements at this price tier require manual correction every 2–3 years as cumulative drift reaches a full day; the ST2528’s 57-second-per-cycle specification means the display will drift approximately one day after roughly 29 years without adjustment. This is among the most accurate mechanical moonphase calibers at this price.

The movement runs at 28,800 vph, producing a noticeably smoother seconds sweep than standard 21,600 vph calibers.

Luminous Moonphase

The V3 upgrade includes BGW9 Super-LumiNova on the moonphase disc itself — the moon and star elements on the disc glow in darkness alongside the lumed hands and indices. Most moonphase watches at this price do not lume the moonphase disc. On the Sugess V3 the moonphase remains readable in low light, which is when a moon display has its most natural viewing context.

Moonphase adjustment warning: Do not operate the moonphase quick-set between 9:00 PM and 3:00 AM. During these hours the calendar mechanism is mid-advance and operating the quick-set risks gear damage. Adjust only outside these hours.

Big Date Window

The big date window uses a dual-disc mechanism — two separate discs carrying the tens and units digits of the date, advancing simultaneously at midnight. The big date format presents a larger, more readable date than a standard single-digit window. The V3 edition improves contrast with a darker background behind the date digits.

Moonphase and Big Date — Combined

The combination of a luminous moonphase and a big date window in a single automatic watch at this price is unusual. Most moonphase watches omit the big date to keep the dial layout manageable; most big date watches omit the moonphase for the same reason. The ST2528 caliber accommodates both simultaneously, with each complication positioned to maintain dial readability — moonphase at 6 o’clock, big date window above at approximately 12 o’clock.

How It Compares in the Sugess Moonphase Range

vs. Sugess S452 Moonphase — The S452 uses the ST2108 with moonphase + pointer date at 40mm / 13mm with no lume. The V3 uses the ST2528 with moonphase + big date at 41mm / 14mm with BGW9 lume throughout. Choose S452 for the pointer date and no-lume dress character; choose V3 for lume readability and the big date window.

vs. Sugess Moonphase Master S426 — The S426 is your highest-impression Sugess moonphase page at 2,656 impressions. Compare the specific complication layouts to ensure the V3 and S426 pages are clearly differentiated.

vs. Carnival IW 527 Moon Phase — The Carnival 527 uses Miyota 9015 at 10.5mm with moonphase only, no lume, at 30m. The V3 is 14mm with moonphase + big date + BGW9 lume at 50m — more complications but thicker profile.

Who Is the Sugess V3 For?

The V3 is built for:

• Buyers who want moonphase + big date simultaneously in a single automatic — the ST2528’s dual complication is the core differentiator
• Blue sandstone dial buyers who want the star-field celestial dial on a moonphase watch specifically
• Lume moonphase buyers — the glowing moonphase disc at night is the V3’s upgrade over the V2 and most competitors at this price
• ST2528 accuracy buyers who want the 57-second-per-cycle moonphase precision

More from Jewelry Addicts

• Sugess Moonphase Master S426 — highest-traffic Sugess moonphase page
• Sugess S452 Moonphase — pointer date moonphase alternative
• Sugess S455 Blue Goldstone — same blue sandstone/goldstone dial in a slim time-only watch
• Carnival IW 527 Moon Phase — slim moonphase alternative at 10.5mm
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