Precious Stones
Diamonds, rubies, emeralds, sapphires and alexandrites — METRONIX GROUP gives you access to the rarest, certified and expertly appraised investment gemstones.
Diamond
The diamond is the quintessential investment gemstone — the only precious stone composed of a single element: carbon. Its absolute hardness of 10 on the Mohs scale, exceptional refractive index and unique chromatic dispersion make it a universally recognised asset. METRONIX GROUP exclusively selects GIA or HRD certified diamonds with full traceability and guaranteed ethical origin.
Applications
- Investment & collection
- Haute couture jewellery
- Precision industry
- Cutting tools
- High-performance optics
Quality criteria (4C)
Colour (D–Z) · Clarity (IF–I3) · Cut (Excellent–Poor) · Carat weight — Our diamonds: D-F colour, IF-VS1 clarity, Excellent cut.
Ruby
Ruby is the world's most precious coloured gemstone. Its intense red hue, due to chromium in its corundum composition, gives it a unique value. Unheated pigeon's blood rubies from Mogok (Myanmar) often exceed diamonds in value per carat. METRONIX GROUP offers certified rubies with origin attestation and full treatment report.
Applications
- High-value investment
- Luxury jewellery
- Prestige watches
- Lasers (synthetic ruby)
- Collection
Quality criteria (4C)
Colour (pigeon's blood preferred) · Clarity · Origin (Myanmar = premium) · Treatment (unheated = significant premium).
Emerald
The emerald is the most precious of green stones — its intense green colour, due to chromium and vanadium, is unmatched in the mineral kingdom. Colombian emeralds (Muzo, Chivor) are the global reference. Nearly all natural emeralds contain inclusions (jardin) which, unlike other stones, are accepted and part of their authenticity.
Applications
- Prestige jewellery
- Heritage investment
- Luxury watches
- Gemological collection
- Fine jewellery art
Quality criteria (4C)
Colour (intensity and green saturation) · Clarity (natural inclusions tolerated) · Origin (Colombia = premium) · Treatment (cedar oil tolerated, resin = depreciation).
Sapphire
Sapphire is the second most precious gemstone after diamond by global value. Its deep Kashmir cornflower blue — unheated — reaches record prices at auction. Sapphire exists in all colours (except red, which is ruby), offering remarkable options for collectors and investors. Its hardness of 9 makes it extremely durable.
Applications
- Royal & prestige jewellery
- Gemological investment
- Watches (sapphire crystal)
- Optics
- Electronics (substrates)
Quality criteria (4C)
Colour (intense velvety blue = Kashmir) · Clarity · Origin (Kashmir, Myanmar = major premiums) · Treatment (unheated = strong premium).
Alexandrite
Alexandrite is the world's rarest and most mysterious stone — its unique alexandritism allows it to change colour dramatically depending on the light source. Discovered in the Russian Ural Mountains in 1830 and named after Tsar Alexander II, a fine alexandrite over one carat with a clear 80%+ colour change from green to red can be worth tens of thousands of euros per carat.
Applications
- Ultra-premium investment
- Gemological collection
- Exceptional jewellery
- Museum pieces
- Medical lasers (synthetic alexandrite)
Quality criteria (4C)
Change strength (% colour changed — ideal: 100%) · Quality of both colours · Clarity · Cut · Weight.
Precious Stones Comparison Table
Invest in Precious Stones
Request a personalised consultation with our GIA-certified gemologists to build your investment gemstone portfolio.