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1.5 Carat Lab-Grown Diamond: Price Guide 2026
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Quick Answer
How much does a 1.5 carat lab diamond cost?
A 1.5 carat lab-grown diamond (round, G color, VS2 clarity, IGI certified) costs $1,100–$1,800 at major retailers. This same stone in natural diamond would cost $9,000–$16,000 — lab diamonds save 85–90% at this size. The 1.5ct threshold delivers a commanding presence on the finger (7.4mm diameter) that represents excellent value in lab-grown form.
📊 1.5ct round G/VS2 IGI: $1,100–$1,800 lab-grown vs $9,000–$16,000 natural. 85–90% savings.
2026 Price Comparison
| Retailer | Round G/VS2 | Oval G/VS2 | Emerald G/VS1 |
|---|---|---|---|
| Clean Origin | $1,100–$1,550 | $1,200–$1,700 | $1,600–$2,200 |
| James Allen | $1,200–$1,700 | $1,300–$1,850 | $1,750–$2,400 |
| Brilliant Earth | $1,450–$2,000 | $1,580–$2,200 | $2,100–$2,900 |
| Blue Nile | $1,280–$1,800 | $1,380–$1,950 | $1,850–$2,550 |
Grade Recommendations for 1.5ct
- Color G: Best value — faces up white, 12–18% cheaper than F. H is fine in yellow gold settings.
- Clarity VS2: Recommended minimum for brilliant cuts. For emerald/Asscher cuts, VS1 is safer.
- Cut Excellent: Non-negotiable for round brilliants at this price point.
- Certification IGI: Standard for lab diamonds. Ensure the grading report is specifically for lab-grown (not synthetic/HPHT specified as natural).
Best Shapes at 1.5ct
At 1.5ct, all shapes make an impact. Three especially shine:
- Oval 1.5ct: Measures ~9.0 × 6.0mm — dramatically elongating, appears even larger than its carat weight. The most popular non-round choice at this size.
- Round 1.5ct: Classic and timeless. 7.4mm diameter commands the finger without being excessive.
- Emerald 1.5ct: Spectacular hall-of-mirrors effect at this size. Requires VS1 clarity but the architectural elegance is unmatched.
Frequently Asked Questions
Yes — 1.5ct is the most meaningful 'upgrade' step from 1ct. The round measures 7.4mm vs 6.5mm for 1ct, which is a clearly visible increase on the finger. If your budget allows it, the 1.5ct threshold is where the stone becomes undeniably presence-commanding without crossing into ostentatious territory. With lab diamonds priced 80% below natural, stepping up from 1ct to 1.5ct lab costs roughly what a 1ct natural diamond does.