14 September 2026
Hannah Murphy
Diamonds are generally considered the world’s most popular gemstone.
Reasons for this include diamond’s supreme hardness and durability, it’s mesmerising optical properties (high refractive index and dispersion = sparkle!) and the symbolism which has been attached to the stone over decades past.
For many, diamonds are the gemstone of choice when it comes to making the ultimate declaration of love, with an engagement ring. In fact, the earliest known recorded diamond engagement ring dates to 1477, when Archduke Maximilian of Austria gave a diamond-set betrothal ring to Mary of Burgundy. It is often described as the first famous diamond engagement ring in history.
Whilst heralded for its influence on love affairs to follow, the ring received by Mary of Burgundy cannot be considered amongst the earliest diamond-set jewellery recorded. Indeed, the earliest surviving diamond-set jewellery dates to around 300 BC, found in present-day Afghanistan, while diamonds themselves are believed to have been collected and valued in ancient India in even earlier times.
Incredibly, natural diamonds can take millions to billions of years to form. Diamond crystals form deep inside Earth’s mantle, usually around 150–200 km below the surface, where temperatures are about 900–1,300°C and pressures are extremely high.
Diamond is the only gemstone composed of only one chemical element, formed of carbon (C). The carbon atoms within each diamond’s crystal structure are strongly bonded, resulting in the unique strength of diamonds. and are brought to the earth’s surface by magma rising to the earth’s surface, with volcanic eruptions leading to the discovery of diamonds within kimberlite or lamproite rocks.
The popularity of natural diamonds has led, in recent years, to significant growth in the market for lab-grown diamonds. Lab-grown diamonds are produced using the same basic principle as natural diamond formation, with carbon crystallised under controlled conditions. Both popular methods – HPHT and CVD – produce diamonds with the same chemical composition and structure as a natural diamond.
Of course, for many there is no substitution for the rarity of natural diamonds and the incredible, unique geological history of stones grown over millions of years, deep within the earth, exhibiting natural inclusions, growth marks and trace elements which stand as a testament to the journey of their formation. As such, it is no surprise that natural diamonds typically hold a stronger resale value than their lab-grown counterparts.
