Natural diamond

Diamonds form under high temperature and pressure that exist only about 160 km (100 miles) or more down in the Earth's mantle, and most formed more than a billion years ago.

Volcanic activity carried them to the surface in magma, forming vertical channels called kimberlite pipes. The discovery of a kimberlite pipe in South Africa in 1869 marks the beginning of the modern diamond era.

The yield is small: in most mines there is on average one part diamond to one million parts of host rock. Canada's Northwest Territories has had diamond mines since Ekati began production in 1998, and the status of each mine as of 2026 is covered in Canadian diamonds.

Chemically, very little. Lab-grown diamonds have the same crystal structure of tightly bonded carbon atoms and nearly the same properties, and natural diamond rates 10 on the Mohs scale. The difference is origin and the faint evidence it leaves. Identifying a lab-grown stone takes advanced instruments, and labs use spectroscopy and fluorescence imaging to read growth patterns and trace impurities. GIA's iD100 desktop instrument helps jewellers screen for lab-grown origin in under two seconds.

Origin has a limit worth knowing. A natural diamond's geographic origin cannot be determined through evaluation of a polished stone. Its origin reports work by matching a polished stone to its original rough diamond. The Kimberley Process is the international scheme for rough diamonds, and it does not follow a polished stone into a ring.

The word diamond on its own describes the material. The US Federal Trade Commission's Jewelry Guides define a diamond as a mineral consisting essentially of pure carbon crystallized in the isometric system, which covers both natural and lab-grown stones. Those guides are American and are not Canadian law, but they show how the trade thinks about the words.

Because the word diamond covers both, sellers use natural or mined to say where a stone came from. The same guides say a lab-grown stone should carry a qualifier such as laboratory-grown immediately before its name, so that it is clear the stone is not mined. In Canada, the Competition Act prohibits any representation to the public that is false or misleading in a material respect. If a stone is sold as natural, the report and the seller's description should agree with that.

Yes, and the report should say so. Some natural diamonds are treated after mining. Colour treatments include irradiation, annealing and HPHT, and clarity treatments include laser drilling and fracture filling. Every GIA diamond grading report lists any known treatment, and GIA does not grade fracture-filled diamonds. Diamond treatments explains the common ones.

Being natural is not the same as being untreated, and it says nothing about quality. A natural diamond can have a high or a low grade on the 4Cs. The report tells you which, and the only way to compare two stones fairly is by their reports and by looking at them.

Price depends on the stone's size and grades and, for a ring, also on the setting and the metal. It is not a fixed value you can count on later.

A ring is not a financial product. What you pay at retail is not what a secondhand buyer will pay, and prices can move either way. Insurance requires an appraisal, and an appraisal is also important for possible resale. A report from GIA or IGI describes the stone and does not set a resale price. If you are deciding between natural and lab-grown, lab-grown vs natural diamonds compares them side by side, and the custom engagement ring service explains how to start a bespoke order around either one.