What are the negatives of lab-grown diamonds?

Lab-grown wins clearly on land disturbance (around 0.07 sq ft per carat vs roughly 100 sq ft for mined) and waste (1 pound vs around 6,000 pounds per carat). The complicated part is energy. A 1ct lab diamond uses around 250 kWh to grow, and roughly 60% of lab production is in India and China where coal is still a major grid source. On clean energy, lab-grown emits well under 1 kg of CO2 per carat. On a coal-heavy grid, that can rise to 6 to 20 kg. Mined diamonds sit much higher, around 100 kg per carat by industry estimates, but the lab-grown story is "much lower," not "zero."

Resale value sits at roughly 10 to 20% of retail, well below mined which typically returns 30 to 50%. By 2026, lab-grown retails about 80 to 85% below the equivalent mined stone, and that gap is still growing because production capacity is still expanding. If the ring is bought to wear long term, the gap does not matter. If it is bought as a store of value or with the intention of upgrading and reselling later, mined holds value better.