For centuries diamonds have lured women up the aisle; in future they may drive them to work as engineers find a use for the precious stones in electric cars and other applications.
From ultra-durable drill bits to semiconductors and optical instruments, industry officials say the uses for diamonds are multiplying and advances in synthetic production have opened the floodgates to ever more innovative applications.
"Diamond as a material is like what steel was in the 1850s and what silicon [the element] was in the 1980s. There will be lots of uses for it in the next 50 years but there is not enough of it in the ground," said Bryant Linares, president and CEO of Massachusetts-based synthetic producer Apollo Diamond.
"We have the potential to make semiconductors which can be faster, and better, than any of the existing available semiconductors," said Linares' father Robert, chairman of the family-controlled business.
The durability of diamonds at high temperatures may revolutionise high-performance processors and could help make the electric car a reality for consumers around the world, he said.
"A lot of the problem with electric cars, power grids and even the computers of the future is dealing with the heat. The use of diamond rather than silicon can reduce the amount of circuitry by up to 80%," he said.
Chemical vapour deposition
One of the major advances in synthetic diamond technology is chemical vapour deposition (CVD), which forms diamonds through a chemical reaction between gases.
CVD can be manipulated to make particular shapes of diamond much more effectively than the older "high pressure, high temperature" (HPHT) method developed by General Electric in the mid-20th century which compresses carbon into diamond using molten metal as a catalyst.
"A lot of the problem with electric cars, power grids and even the computers of the future is dealing with the heat. The use of diamond rather than silicon can reduce the amount of circuitry by up to 80%"
President and CEO of Massachusetts-based synthetic producer Apollo Diamond
That means wafer-thin layers of diamond can be produced for use in microprocessors, or thicker diamonds for other purposes.
The vast majority of diamond used in industrial processes around the world are synthetic. The Diamond Trading Company (DTC), the marketing arm of diamond giant De Beers, says some 200 tonnes of tiny synthetic diamonds, or grit, are used by industry each year - several times total mined production.
With HPHT production, relatively few gem quality stones were produced, and most that were of yellow-brown colour, sometimes known in the trade as "canaries".
But the CVD process gives the producer more control over the diamond produced and, vitally, can produce colourless stones.
De Beers, which controls around 55% of rough diamond sales by value, is also in the synthetic market through its Element Six subsidiary, the leading producer of synthetic diamonds for industrial use.
De Beers estimates the potential market for industrial diamond applications at $50 billion - nearly as much as the $60 billion worldwide gem diamond jewellery sales and several times the $16.7 billion worth of diamonds in that jewellery.
In addition to its hi-tech products, Apollo has its eye on the gem market and believes CVD will eventually produce diamonds to compete openly in the market with mined stones.
"They are chemically, physically and optically identical to mined diamonds," said Robert Linares. "(But) we would prefer the fiancee to know she's got an Apollo diamond."
De Beers says 94% of women
prefer real diamonds
De Beers says synthetic production poses little threat to its market for traditional mined gems, quoting research showing that 94% of women want real - not synthetic - diamonds.
It has developed machines that can tell even colourless synthetic gem diamonds from the real thing, to prevent synthetic diamonds being passed off as mined gems.
"A diamond's value is based on its inherent rarity," DTC global marketing chief Stephen Lussier said. "They are all as old as the world. The world has stopped making diamonds."