Fischer XRF Au750 (75.0%) & Mettler-Toledo Gravimetric Verification
The Rolex Cosmograph Daytona John Mayer II Emerald & Gold Dial 18K Yellow Gold Reference 126508 is a direct Swiss foundry specimen engineered in 18K Yellow Gold Au750 (40.0 mm x 11.9 mm) with a certified Mettler-Toledo mass of 216.8g, Fischer XRF Au750 metallurgical verification, and Rolex Manufacture Cal. 4131 - 72h Power Reserve running at 28,800 vph (±0.8 s/d, 301 deg) with a 72-hour power reserve and 100m / 330 ft - Triplock Screw-Down rating.
Catalogued in our direct Swiss foundry Rolex assay archive under Specimen Code LAB-XRF-126508-W2, this Rolex Cosmograph Daytona John Mayer II Emerald & Gold Dial 18K Yellow Gold Reference 126508 is smelted and CNC-machined in 18K Yellow Gold Au750 (40.0 mm x 11.9 mm). Prior to archival release, the completed assembly is weighed on a calibrated Mettler-Toledo balance at 216.8g and scanned via non-destructive Fischer XRF spectroscopy.
Why Is the Emerald-Green Dial Rolex Daytona Ref. 126508 Known as the "John Mayer" Edition?
The Rolex Cosmograph Daytona "John Mayer" Reference 126508 is a solid 18K yellow gold chronograph featuring a metallic emerald-green sunburst dial and 18K gold tachymeter bezel weighing 216.8g, because its collector nickname originated when horological collector John Mayer highlighted the green-and-gold reference as a modern Geneva icon.
5 Core Foundry & Laboratory Assay Specifications:
- Foundry Specimen Entity: Rolex Cosmograph Daytona John Mayer II Emerald & Gold Dial 18K Yellow Gold — Official Ref. 126508 (Specimen LAB-XRF-126508-W2).
- XRF Metallurgical Assay: 18K Yellow Gold Au750 certified for elemental composition and hallmark integrity.
- Mettler-Toledo Mass: 216.8g verified gravimetric parity matching the authentic manufacture reference.
- Chronometric Calibre: Rolex Manufacture Cal. 4131 - 72h Power Reserve beating at 28,800 vph (4 Hz) with 72-hour reserve and ±0.8 s/d, 301 deg Witschi trace.
- Optical & Pressure Testing: Double anti-reflective sapphire crystal, Vibrant Emerald & Gold Subdials John Mayer II Dial with Solid 18K Gold Applied Hour Markers & Hands, and 100m / 330 ft - Triplock Screw-Down barometric sealing.
Within the Rolex Cosmograph Daytona horological sub-silo, collectors also compare the Rolex Cosmograph Daytona 18K Yellow Gold Deep Crystal Optics Ref. 116508 (216.8g) and the Rolex Cosmograph Daytona Blue Sodalite Stone Dial 18K White Gold Ref. 116519 (153.2g).
- Parent Brand & Cosmograph Daytona Silo Hub: Browse All 289 Certified Rolex Solid 18K Gold & Pt950 Watches
- Technical Research Monograph: Fischer XRF Au750 Spectrometry Watch Authentication SOP-750 (All 5 Journal Monographs)
- Homepage Master Register: Return to 18K FACTORY Homepage (Complete 774-Watch Solid 18K Gold & Pt950 Register)
- All-Brands Catalogue: Explore Complete 12-Maison Horological Catalogue (/shop/)
- Metallurgical & Escrow Verification: Fischer XRF Au750 Protocol • 3-Year Mechanical Warranty • Insured Armored Delivery
What laboratory instruments certify Reference 126508 (Rolex)?
Every 18K Factory specimen is verified on three calibrated instruments on 4K video: a Mettler-Toledo analytical balance (216.8g), a Fischer XRF spectrometer (18K Yellow Gold Au750), and a Witschi Chronoscope (±0.8 s/d, 301 deg).
Does the 216.8g reading match the authentic original Rolex 126508 weight?
Yes. Our CNC foundry machines the 18K Yellow Gold case and bracelet to replicate the exact 216.8g reference mass of the authentic manufacture timepiece.
What are the movement specifications for Reference 126508?
Reference 126508 is powered by the Rolex Manufacture Cal. 4131 - 72h Power Reserve operating at 28,800 vph (4 Hz) with a 72-hour power reserve, regulated across six positions to ±0.8 s/d, 301 deg.
What defines the Rolex Daytona John Mayer Green Dial Ref. 126508?
Rolex Daytona Reference 126508 pairs a solid 18K yellow gold case and Oyster bracelet (216.8g) with a sunburst emerald-green dial and gold-ringed chronograph counters powered by Rolex Manufacture Cal. 4131 - 72h Power Reserve.
Rolex Cosmograph Daytona John Mayer II Emerald & Gold Dial 18K Yellow Gold Ref. 126508 — XRF Certified Edition
Fischer XRF Verified 18K Yellow Gold Au750 • Mettler-Toledo 216.8g • Rolex Manufacture Cal. 4131 - 72h Power Reserve
| Assay Specimen ID & Official Reference | Rolex — Oyster Perpetual Cosmograph Daytona | Ref. 126508 | SKU: LAB-XRF-126508-W2 |
|---|---|
| Fischer XRF Elemental Purity & Alloy | 18K Yellow Gold Au750 — Au750 — 75.0% Pure 18K Gold Bullion (XRF Verified) • Hallmarked Solid Precious Metal |
| Mettler-Toledo Gravimetric Mass (g) | 216.8g — 1:1 Authentic Reference Mass Verified on Mettler-Toledo Analytical Scale |
| Bezel Tolerance, Gem-Setting & Case Dimension | Hand-Finished 18K Yellow Gold Bezel with Anti-Reflective Scratch-Resistant Sapphire Crystal • 216.8g 18K Yellow Gold • 40.0 mm x 11.9 mm |
| Calibre Reference & Witschi Chronometry | Rolex Manufacture Cal. 4131 - 72h Power Reserve — Swiss Super Clone Mechanical Calibre Regulated to ±0.8 s/d, 301 deg |
| Isochronism Frequency & Autonomous Power Reserve | 72-Hour Power Reserve • 28,800 vph (4 Hz) Free-Sprung Balance Wheel |
| Double AR Sapphire Crystal & Barometric Rating | Scratch-Resistant Sapphire Crystal with Double Anti-Reflective Coating • 100m / 330 ft - Triplock Screw-Down |
| Dial Metallurgy & Clasp Hallmark Verification | 40.0 mm x 11.9 mm • Vibrant Emerald & Gold Subdials John Mayer II Dial with Solid 18K Gold Applied Hour Markers & Hands • Integrated 18K Yellow Gold Solid Link Bracelet & Deployant Clasp with Deep Laser Hallmarks |