# GIA vs IGI vs GCAL: Which Diamond Certificate Should You Trust?

**By Ara Talachian** · 2026-06-01

Scientifically, yes — lab-grown and natural tennis bracelets are the same. Both are pure carbon in an identical diamond cubic crystal lattice, with the same Mohs 10 hardness, the same refractive index (2.417), and the same thermal conductivity. Standard diamond testers, loupes, and microscopes cannot tell them apart. The real differences are in origin, characteristic inclusions, UV fluorescence patterns, price (60–80% less for lab-grown), and resale value.

On This Page

[Quick Answer](#quick-answer) [Comparison Guide](#practical-guide) [Expert Breakdown](#expert-breakdown)

Quick Answer: What's the Same, What's Different

-   **Identical:** Chemical composition (pure carbon), crystal structure, Mohs 10 hardness, refractive index 2.417, thermal conductivity, optical performance
-   **Different:** Origin (mantle vs. lab), characteristic inclusions, UV fluorescence patterns, price, resale value
-   **Price gap:** Lab-grown is 60–80% less — a 1ct G VS2 Excellent lab diamond: ~$800–1,200 vs ~$4,000–6,000 natural
-   **Certification:** Both graded by IGI, GIA, GCAL using identical 4Cs standards — reports disclose lab-grown origin
-   **Detection:** Requires specialized spectroscopy — standard tools cannot distinguish them

## Full Property Comparison

Property

Lab-Grown Diamond

Natural Diamond

Chemical composition

Pure carbon (C)

Pure carbon (C)

Crystal structure

Diamond cubic

Diamond cubic

Hardness (Mohs)

10

10

Refractive index

2.417

2.417

Thermal conductivity

~2,000 W/m·K

~2,000 W/m·K

Common type

IIa (CVD), Ib (HPHT)

Ia (~98%), IIa (~2%)

Characteristic inclusions

Growth striations, flux (HPHT)

Mineral inclusions, strain

UV fluorescence

Orange-red (CVD), variable

Blue (common), variable

Price (1ct G VS2 Excellent)

**~$800–1,200**

~$4,000–6,000

Resale value

Lower, declining

Higher, stable

Mining required

**No**

Yes

Certification

IGI, GIA, GCAL

IGI, GIA, GCAL

## Who Should Choose Lab-Grown vs Natural?

**✅ Choose Lab-Grown If You Want…**

Maximum size and quality per budget. Ethical sourcing without mining. A larger, better-graded stone for the same price. DEEVE's lab-grown diamond tennis bracelets start at a fraction of natural diamond prices — same 14K gold setting, same lifetime warranty.

**💎 Choose Natural If You Want…**

Geological rarity and provenance. Stronger long-term resale value. A stone formed over billions of years. Established secondary market liquidity.

## The Two Lab-Grown Methods at a Glance

**☁️ CVD — Chemical Vapor Deposition**

Carbon-rich gas deposited layer-by-layer onto a diamond seed. Lower pressure. Produces Type IIa (high purity, near-colorless). Preferred for gem-quality production. May show orange-red UV fluorescence.

**🔧 HPHT — High Pressure High Temperature**

Replicates mantle conditions: 5–6 GPa, 1,300–1,600°C. Metal flux catalyst. Produces Type Ib diamonds. Faster growth cycle. May show yellow tint at lower grades.

Ready to shop? Explore our collection:

[Shop Lab Grown Diamond Tennis Bracelets →](/collections/diamond-tennis-bracelets) [Tennis Bracelet Hub →](/pages/lab-grown-diamond-tennis-bracelets) [Buying Guide →](/pages/lab-grown-diamond-tennis-bracelet-guide) [FAQ →](/pages/tennis-bracelet-faq)

**Tags:** certification, diamond education, diamond grading, diamond science, diamonds, GIA, IGI, lab-grown diamonds, natural diamonds

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> Source: [DEEVE](https://deeve.ca/blogs/diamond-education/diamond-certification-standards-gia-igi-gcal)