How to Tell if a Diamond is Real

A Practical Guide from Nnamdi The Jeweller

Dear reader,

Diamonds captivate, but imitations abound. As your trusted London jeweller, I provide reliable tests: two at home in minutes, two professional. Shop confidently.

1. Fog Test (30 seconds, no tools)

Diamonds disperse heat 22 times faster than glass.

•  Warm the stone in your palm for 10 seconds.

•  Breathe on it.

•  Time condensation clearance.

Result: 1–2 seconds = likely genuine; 4+ seconds = imitation (e.g., cubic zirconia).

Note: Moissanite clears quickly; continue testing.

2. Water Test (10 seconds, glass of water)

Density: 3.52 g/cm³.

•  Fill glass with room-temperature water.

•  Drop loose stone from 1 cm.

Result: Sinks = consistent with diamond; floats = imitation.

Tip: Submerge mounted ring; genuine pulls downward.

3. Demand GIA Certificate

My diamonds include GIA certificates:

•  GIA (Gemological Institute of America)

Examined at 10× magnification; report laser-inscribed on girdle. Details 4Cs:

•  Cut – proportions, finish

•  Colour – D (colourless) to Z

•  Clarity – FL to I3

•  Carat – weight to hundredth

Verify via QR code or gia.edu/reportcheck. All pieces feature UK Hallmark for gold and platinum authenticity.

4. Professional Verification

Visit my Covent Garden showroom by appointment. In 10 minutes:

•  Weigh on GIA-calibrated scale (±0.001 ct).

•  Inspect at 40× for inclusions.

•  Test conductivity with diamond tester.

•  Match inscription under UV.

Complimentary service; transparency assured. We specialise in GIA-certified diamonds and VVS+ quality for custom work.

Red Flags

•  Undisclosed lab-grown as natural.

•  70% below Rapaport for specs.

•  Refusal of independent testing.

Final Word

Genuine diamonds are heirlooms—verify with certainty. Test at home tonight; bring to Nnamdi The Jeweller for proof.

71-75 Shelton Street, Covent Garden, London, WC2H 9JQ; book via nnamdithejeweller.com; send photo for review.

With clarity and trust,

Nnamdi

Master Jeweller | GIA Graduate Gemmologist

Est. 2016