Lab Grown vs Natural Diamonds: Pros, Cons and Key Differences

As lab grown diamond are becoming increasingly popular in today’s jewellery market, what are the true pros and cons when compared with natural stones?

What are lab grown diamonds?

Lab grown diamonds are man made diamonds with the same atomic carbon structure as natural diamonds, created over days or weeks using advanced technology rather than forming underground over millions of years. The two main methods today are:

HPHT - High pressure high temperature

These diamonds are created just as the name suggests, simulating the conditions in which a natural diamond is created. By using a diamond seed crystal, carbon and a metal catalyst, the synthetic diamond creates itself around the seed host. Temperatures of 1300-1600°C and pressure of 5-6GPa are used. This is equivalent to the  pressure exerted by a commercial jet airplane balanced on a fingertip.

CVD - Chemical vapour deposition

These diamonds are created by using carbon containing gas that is deposited onto a seed crystal in a vacuum chamber. Growth usually takes 4-6 weeks and typically takes longer than HPHT as the process requires pausing many times for removal of a graphite layer so the stone continues to grow as a single crystal. Once growth is finished, the diamonds undergo HPHT treatment to change their colour.

Physical differences

To the naked eye the lab grown and natural diamonds are indistinguishable and can only be identified by using advanced laboratory equipment.

HPHT stones may contain metallic flux inclusions, while CVD stones can contain graphite inclusions. These inclusions, when seen combined with a lack of natural inclusions can point the identifier towards a synthetic conclusion. Further tests such as photoluminescence spectroscopy is then used in a lab to confirm the origin of the diamond and the synthesis method.

So, if lab grown diamonds and natural diamonds look the same, what other pros and cons are there?

Ethical sourcing

Diamond mining has faced ethical scrutiny, particularly in the late 20th century when “blood” or conflict diamonds funded armed conflict, such as during the Sierra Leone civil war (1991–2002). In 2003 the Kimberley process was introduced, regulating import and export and requiring every shipment of rough diamonds to be certified, so that profits can be tracked, remaining conflict free.

Read more about the Kimberley Process here

However, concerns remain around forced and child labour, poor working conditions, unfair hours and low pay in some mines and regions. For many buyers, the assurance that a lab grown diamond was created ethically is a compelling reason to buy synthetic.

Cost

Lab grown diamonds are substantially less expensive than natural diamonds when purchased at retail suppliers for the same carat weight, cut, colour and clarity.

However, one argument that is not considered when the cost of natural diamonds is discussed is second hand markets. Purchasing at auction or through other resale avenues can provide natural diamonds at reduced prices, similar to buying a second hand car rather than a new one. Diamonds can always be removed from current settings, re polished or re cut and reused in newer pieces to suit the buyer.

Colours and sizes

One area where lab grown diamonds excel is availability in larger sizes and fancy colours. Pinks, blues, greens and vivid yellows are all possible at comparatively low prices. In contrast, fancy coloured natural diamonds are rare, with only 0.1% of mined diamonds showing a fancy colour. Large natural fancy coloured examples with good clarity command exceptional prices, the average medium toned blue diamond weighing 1 carat can cost approximately £150,000, with prices seen for a similar lab grown example on auction sites with reserves of £150.

Image courtesy of Gem-A - natural diamond colours

Resale value

Natural diamonds tend to retain their value better than lab grown diamonds. While lab grown stones are cheaper to buy, their resale market is weak and values have fallen in recent years.

Notably, De Beers closed its lab-grown division 'Lightbox' after six years, citing falling prices and a shift toward lab grown diamonds being used mainly in lower-priced fashion jewellery rather than significant, meaningful pieces.

Natural diamonds range in age between 1 billion and 3.5 billion years, giving them wonderful geological and historical significance. Some may have been cut centuries ago, and possibly recut and repolished many times. This sense of history and sentiment is something lab grown diamonds cannot replicate.

Environmental effects

The debate as to whether lab grown diamonds are more environmentally friendly is clouded by the industry’s lack of transparency and conflicting data. A report from the Diamond Producers Association (who represent seven of the world’s largest diamond miners) claims that natural diamond mining produces three times fewer greenhouse gas emissions than growing lab grown diamonds. Conversely, a report by Frost & Sullivan claims that mined diamonds require twice as much energy per carat than those grown in a lab. however, this is assuming all lab grown diamond factories are using renewable energy and casts doubt on the reliability of the report.

Unlike lab grown diamonds energy consumption, however, natural diamonds have other environmental effects. Polluted water due to acid mine drainage and destruction of habitats and landscapes are all consequences of natural diamond mining.

Beyond jewellery

Only about 30% of lab grown diamonds are used in jewellery. The rest have industrial applications in cutting and polishing tools, abrasives, engine parts, dental equipment and even in electrics due to their semi-conductive properties.

Final thoughts

Lab grown and natural diamonds each have unique strengths and weaknesses. Lab grown stones offer ethical certainty, lower retail prices and easy access to rare colours and large sizes. Natural stones retain stronger resale value, carry unmatched history and when purchased second hand can be surprisingly affordable.

The choice between the two comes down to personal priorities, some value the romance of an ancient stone while others value the modern ethics and affordability of lab grown diamonds.