
- by Ahmed Shareek
Blue Star Sapphire Price Guide — What They Cost and Why
- by Ahmed Shareek

Blue is the color most people picture when they hear "star sapphire" — it's the color of the Star of India and most of the famous historical star sapphires. This guide prices blue star sapphire specifically, as a companion to our color-specific guides for pink and purple and violet star sapphire.
Blue star sapphire combines corundum's classic iron-and-titanium blue color mechanism with the same rutile-silk asterism that produces the star in every color of star corundum. Because blue is the color buyers most associate with sapphire generally, a fine blue star sapphire reads as instantly recognizable in a way that pink, purple, or violet star material sometimes needs explaining. For the underlying asterism science, see our Star Sapphire Buyer's Guide.
| Quality tier | What it looks like | Price per carat |
|---|---|---|
| Commercial | Thai or commercial grey-blue, moderate star, 2–5ct | $30–$150 |
| Good | Ceylon grey-blue, sharp star, 2–5ct | $100–$400 |
| Fine | Ceylon blue-grey, sharp star, good body color, 3–5ct | $300–$800 |
| Exceptional, GIA | Ceylon vivid blue, sharp star, transparent body, 3–5ct | $800–$3,000+ |
Our current stock: an 8.09ct cabochon-cut blue star sapphire, AAA grade, unheated, GIA certified, Sri Lanka origin, priced at $4,040 (about $499/ct). At this size and grade, the stone sits at the upper end of the fine tier moving into exceptional — large, clean-star blue material with genuine transparency is scarce enough that the total price reflects both the per-carat rate and the difficulty of finding a stone this size with a sharp, unbroken star at all.
Under $150 per carat typically means a softer, greyer body color and a less defined star — recognizably a blue star sapphire, not a fine one. $300–$800 per carat is where a genuinely attractive blue with a sharp star appears. Above $800 per carat, expect GIA documentation, real transparency in the body (rather than an opaque, milky look), and a crisp six-ray star that holds together as the stone is rotated.
As with every star sapphire color, synthetic blue star corundum is common and can be difficult to distinguish from natural material without lab testing — blue is, if anything, the most commonly synthesized star sapphire color given how recognizable and desirable it is. GIA or equivalent documentation confirming natural origin is the standard expectation above a few hundred dollars. See our natural star sapphire identification guide.
Fine blue star sapphire with a sharp star and good transparency runs $300–$800 per carat, with exceptional GIA-certified stones reaching $800–$3,000+ per carat. Our current 8.09ct GIA-certified example is priced at $4,040 total (about $499/ct).
Within blue corundum specifically, star material is rarer than clean, transparent facet-grade rough, since it requires the dense rutile silk that ordinarily degrades transparency and would be considered a flaw in a faceted stone. Large blue star sapphires (5ct+) with a sharp, unbroken star and genuine transparency, like our 8.09ct stone, are genuinely uncommon.
Currently in stock: our 8.09 ct GIA-certified natural unheated blue star sapphire, cabochon cut, Sri Lanka (Ceylon), priced at $4,040.
Have a question about our blue star sapphire, or want to see it on video before buying? Email crescentgems@gmail.com — we respond within one business day. Free US shipping; 14-day returns on every order.
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