Understanding the Lab-Grown Diamond Process and How We Curate Every Stone
Proposal and gifting seasons bring a surge of interest in lab-grown diamonds, and with that comes a desire for clarity. Buyers want to understand how these diamonds are created, how they compare to natural stones, and most importantly, how to ensure the diamond they choose is truly exceptional.
At By Bonnie, we believe transparency is the foundation of confidence. Whether a client chooses natural or lab-grown, our curation standards ensure every stone meets the highest expectations for brilliance, beauty, and longevity.
How Lab-Grown Diamonds Are Created: Step by Step
Lab-grown diamonds are real diamonds made of pure carbon arranged in the same crystal structure as natural stones. What differs is their formation environment.
1. Selecting the Diamond Seed
The process starts with a thin slice of carbon, called a diamond seed. This seed acts as the foundation upon which carbon atoms will grow.
2. Growth Through HPHT or CVD
There are two primary methods:
HPHT (High Pressure High Temperature)
Replicates the intense conditions deep within the earth. Carbon melts around the seed and crystallizes into a diamond.
CVD (Chemical Vapor Deposition)
Uses a chamber filled with carbon-rich gas. When heated, the carbon separates and deposits onto the seed, building the diamond layer by layer.
3. Crystal Formation
Over several weeks, atoms bond to create a rough diamond. This slow, controlled growth determines the diamond’s structure, clarity potential, and eventual cut quality.
4. Cutting & Polishing
Once grown, the rough diamond is cut and polished the same way as natural stones. The artisan’s skill determines final brilliance, symmetry, and fire.
5. Certification
Lab-grown diamonds receive grading reports from the same institutions that certify natural diamonds. Cut quality, clarity, and color are evaluated with identical standards.
For scientific reference, GIA breaks down these growth processes here
Machine-Made Supply vs. Designer Curation
While lab-grown diamonds are technologically produced, not all stones have equal beauty. The misconception that “all lab diamonds are the same” leads to disappointment when buyers compare mass-produced supply to curated, designer-level stones.
Machine-created does not mean uniformly exceptional. Many lab-grown diamonds on the market exhibit:
- Visible tint
- Poor cut proportions
- Light leakage
- Cloudy or milky fluorescence
- Flat or windowed centers
These issues significantly reduce beauty, even when certificates look “good on paper.” This is why expert curation matters.
How By Bonnie Curates Lab-Grown & Natural Diamonds
Our curation process prioritizes visual performance, not just grading metrics. Each stone is reviewed by hand with the same standards we apply to natural diamonds.
1. Cut Quality First
Cut determines sparkle. We evaluate:
- Crown height
- Pavilion angles
- Depth percentage
- Luster and facet precision
Many lab-grown diamonds are eliminated immediately due to poor optical symmetry.
2. Color & Clarity Screening
We reject stones with undertones (brown, grey, green) that diminish brilliance. Clarity characteristics, especially those unique to CVD or HPHT, are inspected under magnification to ensure long-term durability.
3. Shape Appeal & Ratio
A diamond may have excellent cert grades but lack visual harmony. We assess each shape:
- Ovals for bow-ties and symmetry
- Emeralds for hall of mirrors performance
- Radiants for brilliance distribution
- Pear shapes for balanced shoulders
Our goal is always the same: a stone that performs beautifully in real life, not just on paper.
4. Light Performance Testing
Stones are viewed under multiple lighting environments, daylight, spotlight, backlight, to ensure consistency and fire.
5. Final Design Pairing
Only once a diamond passes all evaluations do we begin matching it to its ideal setting. Many clients choose from our ready-to-ship curated pieces
Why Expert Curation Matters for Longevity
A diamond lasts forever, but only if it’s chosen with intention. Low-quality lab-grown diamonds often lose desirability over time due to:
- Weaker brilliance
- Poor durability in certain clarity structures
- Higher visibility of color shifts
- Less refined faceting
Choosing a curated stone ensures its beauty endures, emotionally and visually, for decades.
At By Bonnie, our goal is not simply to provide more options, but to present the best representation of each category (lab-grown or natural) with the highest craftsmanship.
Schedule a Diamond Review to Compare Stones Side-by-Side
Understanding the lab-grown process is empowering, but seeing diamonds in person is what brings clarity. Our one-on-one consultations allow clients to compare lab-grown and natural stones side-by-side, evaluating brilliance, proportions, sparkle, and emotional resonance.
Explore curated ready to ship options or book a consultation here
Frequently Asked Questions
Lab-grown diamonds are real diamonds created using HPHT or CVD technology. They share the same physical and chemical properties as natural diamonds. The only difference is origin—natural diamonds form over billions of years, while lab-grown diamonds are produced in controlled environments.
No. Lab-grown diamond quality varies significantly depending on growth method, cut precision, clarity, tint, and post-growth treatments. Many stones show weak brilliance or subtle color. Careful curation ensures that only visually exceptional diamonds meet our standards.
We hand-select every stone, prioritizing brilliance, cut quality, symmetry, color consistency, and clarity stability. Even diamonds that appear excellent on paper may be rejected if they do not meet our visual performance criteria during inspection.
Yes. Lab-grown diamonds score 10 on the Mohs scale—the highest hardness rating—making them suitable for everyday wear. Durability concerns arise only when clarity features impact structural integrity, which we thoroughly screen for.
Both can be excellent choices. Lab-grown diamonds offer larger sizes at more accessible price points, while natural diamonds provide rarity and long-term value. A personalized consultation helps determine which aligns better with your priorities, budget, and symbolism.