The same crystal, a cleaner origin
A lab-grown sapphire is corundum. A lab-grown ruby is corundum coloured by chromium. A lab-grown emerald is beryl coloured by chromium or vanadium. In every case the crystal structure, chemistry, hardness, and optical behaviour match the mined equivalent. Under a loupe, side by side, they look identical.
What differs is where the stone came from and how much of its story you can actually trace. Lab-grown gemstones have a short, verifiable supply chain and no country-of-origin ambiguity.
How they're grown
Two methods dominate. Flame fusion and pulled growth (Czochralski) produce large, clean corundum crystals used for most lab sapphires and rubies. Hydrothermal and flux growth mimic the slow mineral conditions that produce natural emerald, and yield stones with the soft inclusions collectors recognise.
The rough is then planned, cut, and polished the same way any gemstone is. There is no shortcut on the finishing.
What is the same
Hardness, refractive index, dispersion, specific gravity, and colour response are all identical to the mined equivalent. A 7.5 sapphire is a 9 on the Mohs scale whether it grew underground or in a chamber. It will wear the same way, take the same polish, and hold the same colour across a lifetime.
Care is also the same: warm soapy water, a soft brush, and a look from a jeweller once a year.
What actually changes
Two things. First, price. A lab-grown ruby or emerald at the same colour, clarity, and cut typically costs a fraction of a mined equivalent, especially in larger sizes where mined material becomes scarce. Second, availability: colours that are rare in nature (a true unheated Kashmir-style blue, an intense Colombian-style green) are reachable at reasonable prices.
Resale for coloured stones has always been thin, mined or lab, so treat any piece as something to wear rather than to trade.
How to buy one well
Judge colour first. In coloured stones, colour drives 60 to 80% of the value: hue, saturation, and tone. Then clarity — eye-clean is the bar, and inclusions that don't threaten durability are fine. Cut matters last but shouldn't be neglected: a well-cut stone shows more colour and more life.
Ask for a report from a recognised lab. For lab-grown coloured stones the report should note the growth method (flame fusion, Czochralski, hydrothermal, flux) alongside the usual specs.
Where Harlow sits
The Vault starts with lab-grown diamonds. Sapphires, rubies, and emeralds are on the near horizon, held to the same standard: reviewed in person, sold with a report, and honest about origin.
If you're looking for a specific colour or size that isn't listed yet, tell us — we can check availability with our supplier.