Prix par carat :
€1.749,41
Acheter une pierre non sertie, c'est choisir librement : votre pierre, et votre propre création de bijou.
5.18 carat cushion-cut blue sapphire, heat-treated, measuring 10.00 × 8.42 × 7.03 mm. Crescent Gems bought this stone directly in Sri Lanka, through our Colombo, Beruwala and Ratnapura buying offices; the Ceylon origin given on this page is our own sourcing record. It is accompanied by GIA Sapphire Report #6237949095, which covers species, variety, weight, measurements, color, transparency, cutting style and treatment; the report's Geographic Origin field reads "Not Requested". The report's Comments record that the color appearance of this stone is described in the trade as "Royal Blue" — the trade's term, which GIA is reporting. The report's Color field reads Deep Blue. In our own assessment the stone has inclusions visible under 10×; they are natural to the stone and the price reflects them. At 5.18 carats, a substantial center stone or collector piece.
Expert Opinion
Ahmed Shareek's Assessment
"This is one of the larger Ceylon blue sapphires we've carried this year — 5.18 carats, with strong light return through the cushion. GIA Sapphire Report #6237949095 covers species, variety, weight, measurements, color, transparency, cutting style and treatment. Two things stated on this page are ours and not the report's: the clarity, which is our own assessment, and the origin. We bought the stone in Sri Lanka ourselves, and that is the whole basis for the Ceylon origin given here."
Rarity Analysis
Fine blue sapphire over 5 carats is a small fraction of what reaches the market in any given year — most commercial blue sapphire sells well under 2 carats.
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Color: The report's Color field reads Deep Blue. Its Comments record that the color appearance of this stone is described in the trade as "Royal Blue" — the trade's term, which GIA is reporting.
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Size: The report records a weight of 5.18 carats and measurements of 10.00 × 8.42 × 7.03 mm.
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Treatment: The report's Additional Results field reads Heated.
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Cut: The report gives three separate fields: Shape — Cushion; Cutting Style: Crown — Brilliant Cut; Cutting Style: Pavilion — Step Cut. They are reproduced here as three separate facts.
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Documentation: GIA Sapphire Report #6237949095, dated 21 May 2026, records species, variety, weight, measurements, color, transparency, cutting style and treatment.
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Combined effect: The table below lists the report's printed field values and, separately, the two attributes that are Crescent Gems' own — the clarity and the origin.
Buying Guidance
A few practical points to weigh before purchasing this specific stone:
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Read the report alongside the listing. GIA Sapphire Report #6237949095 is the source for the species, variety, weight, measurements, color, transparency, cutting style and treatment stated here. The clarity note and the origin are Crescent Gems' own.
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Plan the setting around a substantial center stone. At 10.00 × 8.42 × 7.03 mm and 5.18 carats, this stone needs a mount with prongs positioned to protect the cushion's corners, which are the most vulnerable point on any cushion-cut stone.
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Confirm treatment disclosure when comparison-shopping. This stone's GIA report states its heat treatment plainly — treat any comparable stone's listing that omits or is vague about treatment as a red flag, not an assumption of "untreated."
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Check the report number yourself. Report #6237949095 can be looked up on GIA's own Report Check service. What you will find there is the species, variety, weight, measurements, color, transparency, cutting style and treatment — and a Geographic Origin field that reads "Not Requested".
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Use the Try Before You Buy option if you would like to see the stone in hand before finalizing the purchase.
Learn More About This Gemstone
Gemstone Data — At a Glance
| Item # |
CG8312 |
| Carat Weight |
5.18 ct |
| Species / Variety |
Natural Corundum — Sapphire |
| Shape / Cut |
Cushion; crown Brilliant Cut, pavilion Step Cut |
| Dimensions |
10.00 × 8.42 × 7.03 mm |
| Color |
Deep Blue |
| Treatment |
Heated (disclosed on GIA report) |
| Origin |
Sri Lanka (Ceylon) — Crescent Gems' own sourcing record |
| Geographic Origin on the GIA report |
Not Requested |
| Clarity |
Inclusions visible under 10× — our own assessment; GIA colored-stone reports carry no clarity grade |
| Transparency |
Transparent |
| Hardness |
9 (Mohs) |
| Certification |
GIA Report #6237949095 |
Features
- SKU: CG8312
- Carat Weight: 5.18 carats
- Variety: Blue Sapphire
- Shape: Cushion
- Cutting Style — Crown: Brilliant Cut
- Cutting Style — Pavilion: Step Cut
- Dimensions: 10.00 × 8.42 × 7.03 mm
- Species: Natural Corundum
- Origin: Sri Lanka (Ceylon) — Crescent Gems' own sourcing record
- Geographic Origin on the GIA report: Not Requested
- Treatment: Heated
- Color: Deep Blue
- Transparency: Transparent
- Clarity: Inclusions visible under 10× — our own assessment, not a GIA grade
- Certification: GIA Report #6237949095
- Hardness: 9 on the Mohs scale
Care
- Clean with lukewarm water and mild soap using a soft brush
- Store separately to avoid surface contact
- Remove before heavy physical activity
- Avoid ultrasonic or steam cleaners
One of a Kind
This is a single natural gemstone, not a manufactured or lab-created replica — no two sapphires form with identical color, inclusions, and internal character. Once this stone sells, it's gone; there is no duplicate. What you see documented on the GIA report is the exact, individual stone you receive.
What's included with this Blue Sapphire
- GIA Report #6237949095
- Gemstone packed in a gem sleeve
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