Why In News?

Lab-grown diamonds are considered a sustainable alternative to mined stones because they eliminate the environmental destruction, forced labor, and conflict associated with traditional mining.

What are Lab-Grown Diamonds (LGDs)?

LGDs are synthetic diamonds produced in controlled laboratory settings that exhibit the identical crystal structure, chemical composition, and physical properties as natural, earth-mined diamonds.

  • Both varieties consist of pure carbon organized in an isometric-tetrahedral crystal lattice, as confirmed by the Gemological Institute of America (GIA).

Under the Bureau of Indian Standards (BIS) Standard IS 15766:2007, manufacturers cannot sell synthetic stones under the unqualified term "diamond" and must explicitly label them as "synthetic diamonds."

Manufacturing Methods

High Pressure High Temperature (HPHT): Process replicates the Earth’s upper mantle conditions. 

  • A microscopic diamond seed sits in a capsule with graphite and a molten transition metal catalyst (iron or cobalt). 

  • The system reaches temperatures of 1300°C to 1600°C and pressures exceeding 870,000 psi. HPHT growth yields cuboctahedron-shaped crystals with 14 distinct growth directions.

Chemical Vapour Deposition (CVD): Replicates low-pressure astronomical diamond formation. 

  • Diamond seeds reside in a vacuum chamber filled with a hydrocarbon gas mixture (methane and hydrogen) heated to 900°C to 1200°C. 

  • A microwave plasma beam breaks down gas molecules, forcing carbon atoms to deposit layer-by-layer. 

  • CVD produces cubic-shaped crystals grown in single directional layers.

How are Lab-Grown Diamonds Different from Natural Diamonds?

Feature

Natural Diamonds

Lab-Grown Diamonds (LGD)

Formation Timeline

1 to 3 billion years in the mantle

3 to 4 weeks in a reactor

Growth Morphology

Octahedral geological crystal habits

Cuboctahedron (HPHT) or Cubic (CVD)

Lattice Catalysts

Natural nitrogen/boron impurities

Metallic flux residues (HPHT) or growth strains (CVD)

Market Cost

$1,800 to $12,000 per carat

~$800 per carat

Carbon Footprint

Massive fuel-driven open-pit excavation

High electrical energy but lower geological footprint

Applications of Lab-Grown Diamonds

High-Power Semiconductors: LGD substrates enable electronic chips to operate at higher speeds with lower power consumption, supporting 5G networks and space electronics.

Defence and Space: LGDs serve as heat sinks and radiation-hardened window panes for satellites and advanced laser optics.

Quantum and Medical: Pure CVD-grown diamonds with nitrogen-vacancy centers integrate into quantum magnetic sensors and industrial surgical scalpel coatings.

India's Role in the Lab-Grown Diamond Industry

Global Polishing Hub: Surat, Gujarat cuts and polishes over 90% of the world’s diamonds, employing over 2 million to 5 million people.

Indigenous Technological Transition: The Ministry of Finance’s Union Budget 2023-24 allocated a five-year research grant of Rs. 242.96 crores to IIT-Madras to establish the India Centre for Lab-Grown Diamond (InCent-LGD). 

Export Growth Acceleration: According to data from the Department of Commercial Intelligence and Statistics (DGCIS), India's exports of cut and polished lab-grown diamonds grew rapidly from $237.89 million in 2017-18 to $1,348.24 million in 2021-22

Source: THEHINDU

PRACTICE QUESTION

Q. With reference to Lab-Grown Diamonds (LGDs), consider the following statements:
  1. Under the High Pressure High Temperature (HPHT) method, diamonds grow in a cubic shape, whereas Chemical Vapour Deposition (CVD) yields a cuboctahedron shape.
  2. The Bureau of Indian Standards (BIS) mandates that the term "diamond" alone can be used to refer to both natural and synthetic diamonds.
  3. Lab-grown diamonds have the exact same physical and chemical properties as natural diamonds.
Which of the statements given above is/are correct?
A) 1 and 2 only
B) 3 only
C) 2 and 3 only
D) 1, 2 and 3
Answer: B) 3 only 
Explanation: 
Statement 1 is incorrect: HPHT crystals generally form in a cuboctahedron shape, whereas CVD growth yields a cubic or tabular shape.  
Statement 2 is incorrect: The Bureau of Indian Standards mandates that the unqualified word "diamond" can only be used for natural diamonds; lab-grown versions must explicitly use terms like "laboratory-grown diamond".  
Statement 3 is correct: Lab-grown diamonds share the identical chemical composition (pure carbon), crystal lattice, and physical-optical properties as natural diamonds.