For billions of years, nature has been producing diamonds deep beneath the Earth’s surface under immense pressure and temperatures exceeding 1,000°C. Every natural diamond is the result of a geological journey unlike any other gemstone, carrying with it a unique record of the Earth’s history.

Today, laboratory-grown diamonds are manufactured in controlled environments over a period of weeks rather than billions of years. While they possess the same crystal structure as diamond, the economics of their production are almost the complete inverse of nature.

Nature’s Ratio: Large Diamonds Are Exceptionally Rare

Natural diamond deposits follow a remarkably predictable size distribution.

The overwhelming majority of diamonds recovered from mines around the world are small crystals. As crystal size increases, rarity increases exponentially. Large gem-quality rough diamonds are exceptionally uncommon because their growth requires an uninterrupted geological environment over immense periods of time. Even minor changes in pressure, temperature, or surrounding chemistry can halt growth or fracture a developing crystal.

This means that:

• Small diamonds make up the vast majority of natural production.
• Medium-sized diamonds are considerably less common.
• Large diamonds are exceptionally rare.
• Very large, high-quality diamonds are among the rarest natural materials on Earth.

This natural scarcity is why diamonds above several carats increase dramatically in value. Their rarity is not created by marketing—it is governed by geology.

Laboratory Production: The Reverse Distribution

Laboratory-grown diamonds operate under a completely different economic model.

Manufacturers begin with a tiny diamond seed and grow additional carbon onto it using either High Pressure High Temperature (HPHT) or Chemical Vapour Deposition (CVD) technology.

Unlike mining, where large diamonds are rarely discovered, laboratory production often aims to grow the largest crystal economically possible.

The production costs of a laboratory-grown diamond are concentrated in operating the equipment rather than discovering the crystal. Once a growth cycle has begun, extending growth to produce a larger crystal is frequently more profitable than manufacturing numerous small stones.

As a result:

• Larger laboratory-grown rough is increasingly common.
• Multiple large diamonds can be produced from a single manufacturing facility every month.
• Production volumes are limited primarily by equipment capacity and electricity costs rather than geological rarity.

In many modern factories, larger diamonds are actually preferred because they provide greater manufacturing flexibility and can be cut into multiple finished stones.

The distribution therefore becomes almost the reverse of nature.

Billions of Years vs Several Weeks

Natural diamonds typically formed between one and three billion years ago within the Earth’s mantle at depths approaching 150 to 250 kilometres.

Their growth occurred slowly under constantly changing geological conditions before volcanic eruptions transported them to the Earth’s surface through kimberlite and lamproite pipes.

Laboratory-grown diamonds, by comparison, are produced in controlled chambers over several weeks.

Every variable—including temperature, pressure, gas composition and growth rate—is carefully managed by technicians rather than nature.

A Record of Earth’s History

One of the most fascinating differences lies within the crystal itself.

Natural diamonds contain microscopic traces of the environment in which they formed. These include tiny amounts of nitrogen, boron, hydrogen and numerous other trace elements that became incorporated into the crystal lattice over geological time.

Many natural diamonds also contain microscopic mineral inclusions originating from deep within the Earth’s mantle. These tiny crystals provide scientists with valuable information about regions of the Earth that can never be directly sampled.

In effect, every natural diamond is a geological time capsule.

Laboratory-grown diamonds, however, are produced from highly purified carbon sources under carefully controlled conditions. Their objective is consistency rather than geological complexity.

Consequently, laboratory-grown diamonds are composed almost entirely of carbon, with very low levels of naturally occurring trace elements. Depending on the manufacturing process, they may instead exhibit characteristics associated with their production, including metallic catalyst residues in some HPHT-grown diamonds or growth-related structural features in CVD-grown diamonds.

Rather than recording billions of years of Earth’s geological history, laboratory-grown diamonds primarily reflect the manufacturing process used to create them.

Why These Differences Matter

Although natural and laboratory-grown diamonds share the same fundamental crystal structure and hardness, their origin is entirely different.

Natural diamonds represent an irreplaceable finite resource created by geological processes that cannot be replicated by nature within any human timescale. Their rarity is determined by billions of years of Earth history and the extremely low probability of large crystal formation.

Laboratory-grown diamonds represent an impressive technological achievement. They are manufactured products whose supply is governed by industrial capacity, advances in production technology and manufacturing costs.

Understanding these differences is essential when assessing rarity, long-term availability and market value. As laboratory production continues to expand, large laboratory-grown diamonds are expected to become increasingly accessible, while large natural diamonds will remain among the rarest and most sought-after treasures ever created by nature.

The DCLA Perspective

At the Diamond Certification Laboratory of Australia (DCLA), every diamond is identified and graded according to internationally recognised gemmological standards. Whether natural or laboratory-grown, accurate identification allows consumers, jewellers and collectors to make informed decisions based on origin, rarity and value.

While both categories have their place within today’s jewellery market, they should never be considered equivalent in terms of geological origin. One is a remarkable product of Earth’s natural history, while the other is a remarkable achievement of modern science.

Understanding that distinction remains fundamental to informed purchasing and responsible disclosure throughout the diamond industry.