Chatham Education: How We Grow Gemstones – Chatham Inc.

How We Grow

Chatham is proud to be the pioneer of lab-grown colored gemstones, combining scientific innovation with a deep respect for the natural processes that create the world's most beautiful gems.

Growing Gemstone Crystals

Every Chatham gemstone begins with a thin slice of a mined crystal, known as a seed, placed inside a Carroll Chatham-designed and engineered platinum crucible. The chamber is filled with a molten solution containing the precise chemical ingredients required for crystal growth. This liquid solution, sometimes referred to as a flux solution, exists only at temperatures exceeding 1100 degrees Celsius, resembling the interior of a volcano.

Once sealed, the crucible remains undisturbed for a period of time. Depending on the gemstone variety, growth can take six months to one full year.

During this time, temperature and chemical balance are maintained with extreme precision to replicate the geological environment where each gem naturally forms. Slowly, atoms migrate through the molten solution and attach themselves to the seed crystal, allowing the gemstone to grow in its natural crystalline structure.

The result is gemstone rough that is chemically and structurally identical to material found in nature. This method, known as flux growth, mirrors natural formation far more closely than faster, lower-cost methods such as flame fusion.

For Chatham, the extended growth period is essential. Exceptional color, clarity, and authenticity cannot be rushed.

Innovation Through Patience

Opening a growth crucible after ten months is still a moment of anticipation and discovery. Some runs produce extraordinary crystals; others reveal opportunities for improvement. Continuous experimentation and refinement remain central to Chatham's culture of innovation.

Crystal growth is very fragile. Even minor disturbances, such as seismic activity or a sustained power interruption, can halt growth entirely. A temperature variation lasting more than a few minutes becomes permanently visible within the crystal. This fragility led Chatham to expand production facilities globally beginning in 1989, ensuring stability and consistency across multiple locations.

Steps Toward a Greener Planet

Responsibly Grown

Energy Efficiency

One of the most remarkable achievements in Chatham's development has been maintaining crystal growth temperatures near 1200 degrees Celsius for an entire year without measurable fluctuation. Our flux furnaces, approximately the size of a 50-gallon cylinder, are engineered for exceptional thermal stability and efficiency. While the interior reaches volcanic temperatures, the exterior remains near room temperature. This design not only conserves energy, but more importantly, ensures the consistency required for successful crystal growth.

Environmental Impact

The specialized flux material used in growth is a proprietary formulation composed of ultra-pure chemicals, often described as "five-nines" purity, or 99.999% pure. The flux itself is reusable and does not degrade over time only the elemental ingredients of the gemstone are consumed during the growth. Chatham further extends sustainability by reusing critical equipment, including the platinum crucibles in which crystal growth occurs.

Preserving the Planet

Compared with traditional mining, laboratory growth significantly reduces land disruption and material extraction. While no gemstone production is entirely impact-free, controlled laboratory growth generally results in a lighter environmental footprint than large-scale mining operations. Chatham extends its commitment to sustainability by planting a tree for every jewelry purchase, creating beauty that gives back to the earth.

From Crystal to Gemstone

Why Lab-Grown Gems Require Investment

The Value of Time

The primary cost of growing gemstones is not raw material. It is time.

Each growth cycle can produce roughly 10,000 carats of crystal, yet only a fraction ultimately becomes finished gemstones.

Uncompromising Standards

Natural inclusions form during growth just as they do in nature, requiring cutters to remove about 70-80% of the rough material to achieve Chatham's standards of color and clarity. Additional crystals must also be reserved as seeds for future growth.

Gemstone Mapping

Each crystal is carefully studied to determine the optimal cutting plan based on its natural structure and internal characteristics. Traditional gemstone shapes are crafted alonside proprietary designs developed exclusively for Chatham collections, including the Onion or Flame Cut.

Inspired by Nature

Chatham gemstones ultimately represent a union of science, patience, crafstmanship, and respect for nature, allowing extraordinary color gemstones to form not by imitation, but by guiding nature itself under carefully controlled conditions.

How Diamonds Grow

Unlike most gemstones, diamond consists of a single element: carbon. This purity simplifies certain aspects of crystal growth while simultaneously demanding extreme precision in environmental control.

Chatham grows diamonds using two advanced methods: HPHT & CVD.

High Pressure High Temperature (HPHT)

The HPHT method replicates the natural geological forces responsible for diamond formation beneath the earth's surface. Diamond crystals are grown under approximately 725,000 PSI (pounds per square inch) of pressure and temperature near 1300 degrees Celsius. Without these extreme conditions, carbon would form graphite rather than diamond. Diamonds produced through HPHT growth are known for exceptional color and crystal integrity.

Chemical Vapor Deposition (CVD)

CVD technology grows diamond crystals atom by atom using advanced plasma science. Methane gas is energized using microwave plasma, breaking molecular bonds and releasing carbon atoms. These atoms settle onto a diamond seed crystal, gradually building a diamond layer one atom at a time. Despite technological advances, CVD diamond growth remains highly complex, requiring constant computer-controlled precision and extensive scientific expertise.

Responsible Luxury

Chatham is proudly certified by the Responsible Jewellery Council (RJC), reflecting its commitment to ethical, sustainable, and transparent business practices. By adhering to the RJC's strict standards, Chatham ensures accountability across its operations, from gemstone creation to jewelry design, reinforcing its dedication to responsible sourcing and integrity in the jewelry industry.

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Clarifying Myths & Misconceptions

Answers to Common Questions

We've received a number of inquiries throughout the years, and these are some of the most frequently asked questions.

Do diamonds really take billions of years to form?

There is no scientific evidence suggesting that diamonds require billions of years to form. For that claim to be true, the Earth's conditions would need to remain perfectly stable for billions of years, without fluctuations in temperature and pressure, which is not how geological environments behave.

What is often misunderstood is the difference between diamond formation and diamond discovery. While diamonds may take millions or even billions of years to travel from deep within the Earth to the surface through volcanic activity, the actual crystal growth process itself occurs under the right conditions of heat, pressure, and carbon availability, not simply over vast spans of time.

How much can a customer save by choosing a lab-grown diamond compared to a mined diamond of similar quality?

Growing diamonds is technologically demanding and capital intensive. However, growth in a lab eliminates many costs associated with large-scale mining operations. As a result, Chatham diamonds typically offer 30-80% savings compared to mined diamonds of comparable size and quality, with price advantages increasing as diamond size and quality rises.

What is the environmental impact of growing gemstones in a laboratory compared to mining?

Few products in the jewelry industry are entirely without environmental impact. The meaningful comparison lies in a relative footprint. Independent academic analysis, including research conducted at Stanford University, has suggested that, even accounting for equipment manufacturing and energy usage, the carbon footprint of a lab-grown diamond may be approximately 20% of that associated with mined diamond production.

Diamond mining requires the extraction and crushing of vast quantities of rock, often up to ten tons per carat of diamond rough, creating large open pits visible from space and permanently altering landscapes.

By contrast, lab growth relies primarily on scientific expertise, precision engineering, and advanced computational control. The true challenge is not energy consumption alone, but the highly specialized chemistry, physics, and proprietary knowledge required to successfully grow gem-quality stones.

Why are earth-mined gemstones sometimes referred to as 'natural?'

It's common to hear different terms used to describe the same products, as the jewelry industry does not follow a universal standard. For example, lab-grown and lab-created are synonymous and both accurately describe a gemstone grown in a laboratory environment.

When referring to gemstones extracted from the earth, Chatham uses the terms earth-mined or mined. While many in the industry use the term natural, this terminology is often debated within the lab-grown community. Both mined and lab-grown gemstones are genuine crystals that form naturally under the right conditions, the difference lies in the environment in which they are grown.

Using the term natural exclusively for mined gemstones can unintentionally imply that lab-grown gemstones are not natural, which is misleading. For this reason, Chatham prefers terminology that clearly distinguishes a gemstone's origin without suggesting a difference in authenticity or composition.

Are lab-grown grown gemstones and jewelry a good investment?

Jewelry and gemstones are best appreciated for their sentimental value rather than their monetary value. They serve as lasting symbols of life's most meaningful moments, carrying personal stories and memories from one generation to the next. While gold jewelry will always retain an intrinsic market value, the true value of a Chatham lab-grown gemstone lies in its beauty, quality, and the confidence provided by our lifetime warranty ensuring a piece that can be worn, cherished, and enjoyed for years to come.

Can lab-grown and earth-mined gemstones coexist?

Yes! Lab-grown and earth-mined gemstones can and should coexist. Rather than competing with one another, they expand consumer choice by offering distinct value propositions. There is a place in the market for both.

Some consumers are drawn to the beauty and unique characteristics of mined gemstones, while others appreciate the innovation, responsibility, and scientific achievement behind lab-grown gems. Each appeals to different preferences, priorities, and purchasing motivations.

Retailers who offer both options are best positioned to serve the diverse needs of today's consumers. As the jewelry industry continues to evolve, embracing both categories reflects a modern, customer-focused approach that recognizes the value each brings to the marketplace.

The Chatham Oracle