Lab Grown Diamonds (LGDs)

Lab Grown Diamonds (LGDs) are synthetic diamonds produced in controlled laboratory conditions using advanced technological processes that replicate the natural formation of diamonds beneath the Earth’s crust. Chemically, physically, and optically identical to mined diamonds, LGDs have gained increasing global acceptance as sustainable and ethically sourced alternatives to natural diamonds. Their development represents a significant intersection between material science, technology, and the modern jewellery industry.

Definition and Composition

Lab grown diamonds are composed of pure carbon atoms arranged in a crystalline cubic structure, the same as natural diamonds. They exhibit the same hardness (10 on the Mohs scale), refractive index, and thermal conductivity. The key distinction lies in their origin — while natural diamonds form over billions of years under intense heat and pressure deep within the Earth, lab grown diamonds are created within a few weeks inside laboratories using high-pressure, high-temperature (HPHT) or chemical vapour deposition (CVD) techniques.
These diamonds are not to be confused with diamond simulants such as cubic zirconia or moissanite, which only mimic the appearance of diamonds but differ in chemical and physical properties. LGDs are true diamonds by all scientific definitions.

Historical Background and Development

The synthesis of diamonds has been a scientific pursuit since the 19th century. The first successful creation of a synthetic diamond was achieved in 1954 by General Electric (GE) in the United States using the HPHT method. Initially, synthetic diamonds were small and primarily used for industrial applications such as cutting, drilling, and polishing tools due to their superior hardness.
By the early 21st century, advances in CVD technology enabled the production of gem-quality lab grown diamonds, leading to their commercial introduction in the jewellery market. Companies such as De Beers (through its Lightbox brand) and numerous specialised producers in India, China, and the United States now manufacture LGDs on an industrial scale, making them more affordable and widely available than ever before.

Methods of Production

There are two principal techniques used to manufacture lab grown diamonds:

1. High Pressure High Temperature (HPHT)This method replicates the natural conditions under which diamonds form deep within the Earth. A small diamond seed is placed in carbon-rich material and subjected to pressures of about 5–6 GPa and temperatures exceeding 1,500°C. Carbon atoms crystallise around the seed, gradually forming a larger diamond.
   • Advantages: Produces large, high-quality stones quickly.
   • Drawbacks: High energy consumption and potential for metallic inclusions.
2. Chemical Vapour Deposition (CVD)This modern process involves placing a diamond seed in a vacuum chamber filled with carbon-containing gases such as methane. When these gases are ionised by microwaves, carbon atoms deposit layer by layer onto the seed, forming a diamond crystal.
   • Advantages: Produces high-purity, type IIa diamonds with minimal inclusions.
   • Drawbacks: Requires precise control and longer growth periods.

Each method can be further refined to control colour, clarity, and crystal size. Post-growth treatments such as annealing or irradiation may be applied to enhance optical properties.

Physical and Optical Properties

Lab grown diamonds possess the same measurable characteristics as their natural counterparts:

• Hardness: 10 on the Mohs scale.
• Density: Approximately 3.52 g/cm³.
• Refractive Index: 2.42, producing exceptional brilliance.
• Thermal Conductivity: Among the highest of any known material.

They are graded using the same “Four Cs” — Cut, Colour, Clarity, and Carat Weight — as established by the Gemological Institute of America (GIA). Professional gem laboratories issue certificates identifying diamonds as “lab grown” while confirming their authenticity and quality.

Economic and Industrial Importance

The commercial production of LGDs has transformed both the jewellery market and industrial sectors. Economically, lab grown diamonds cost 30–60% less than mined diamonds of similar quality, making them increasingly attractive to consumers seeking affordability and transparency.
Key industrial uses include:

• Precision cutting and drilling tools
• Semiconductors and electronics due to their superior thermal conductivity
• High-performance optics and lasers
• Quantum computing and photonics research, where diamond’s unique atomic lattice is utilised for quantum sensors and data storage.

India has emerged as one of the global leaders in LGD production, with cities like Surat and Mumbai hosting advanced manufacturing facilities. The Government of India has even classified LGDs as a priority sector for innovation under its “Make in India” initiative.

Environmental and Ethical Aspects

One of the major advantages of LGDs lies in their environmental and ethical sustainability. Unlike mined diamonds, which require extensive excavation and often raise concerns over ecological degradation and human rights issues, lab grown diamonds are produced with minimal land disturbance and controlled working conditions.
Environmental benefits include:

• Lower carbon emissions and reduced energy use (particularly in renewable-energy-powered facilities).
• No habitat destruction or water pollution associated with mining.
• Traceable supply chains, ensuring conflict-free origins.

However, the environmental impact varies depending on energy sources used in production. HPHT processes powered by fossil fuels can still have a notable carbon footprint, whereas CVD operations using renewable electricity are significantly cleaner.

Market Trends and Consumer Perception

The global market for LGDs has expanded rapidly over the past decade. By 2025, lab grown diamonds are estimated to account for nearly 15–20% of total diamond jewellery sales. Increasing consumer awareness of sustainability, combined with advancements in production technology, has reduced the social stigma once attached to synthetic diamonds.
Millennial and Gen Z consumers in particular favour LGDs for their ethical sourcing, affordability, and identical beauty. Major jewellery brands now include lab grown collections, while global certification agencies such as the GIA and IGI have established standardised grading systems for LGDs.
Despite this, some traditionalists and luxury brands continue to distinguish between natural and lab grown stones, arguing that the rarity and geological history of natural diamonds confer intrinsic emotional and investment value that LGDs cannot replicate.

Challenges and Criticisms

While LGDs offer many advantages, they also face certain challenges:

• Market volatility: Rapid expansion has led to fluctuating prices and supply chain saturation.
• Energy consumption: Especially in HPHT systems, which can offset some environmental benefits.
• Consumer confusion: Misleading marketing by unregulated sellers can blur distinctions between lab grown and simulant products.
• Resale value: LGDs often depreciate more quickly than natural diamonds in secondary markets due to their replicable nature.

Regulatory bodies and trade organisations are developing clearer labelling standards to maintain transparency and consumer trust in both diamond categories.

Future Prospects and Technological Innovation

The future of lab grown diamonds extends far beyond the jewellery industry. Advances in material science are enabling applications in next-generation electronics, quantum computing, and space technologies. Ultra-pure LGDs are being engineered for use in radiation detectors, high-power transistors, and thermal management systems.
In the jewellery sector, continuous improvements in growth techniques are yielding larger, more colourless, and flawless stones at reduced costs. The convergence of artificial intelligence, automation, and precision engineering is likely to make LGD production increasingly efficient and sustainable.