Blue Star Sapphire Price Guide — What They Cost and Why

Blue is the color most people picture when they hear "star sapphire" — the color of the Star of India, the 563-carat star sapphire held by the American Museum of Natural History. This guide prices blue star sapphire specifically, as a companion to our color-specific guides for pink and purple and violet star sapphire.

What Makes Blue Star Sapphire the Benchmark Color

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. GIA describes the effect plainly: it is "caused by reflections from tiny, needle-like inclusions that are oriented in several specific directions." Because blue is the color buyers most associate with sapphire generally, a blue star sapphire needs less explaining than pink, purple, or violet star material. For the underlying asterism science, see our Star Sapphire Buyer's Guide.

Blue Star Sapphire Price by Per-Carat Band (2026)

The table below sets out the per-carat levels blue star sapphire is commonly offered at, and what tends to change between them. The headings matter: these are price bands, not quality grades. No laboratory grades asterism, so nothing here is a grading scale, and our own stone is not placed on it.

Approximate market orientation as at September 2026, for natural blue star sapphire sold loose. These are not measured figures, not a survey, and not our own sales data, and they are not offers. The bands carry no size qualifier, so a larger stone's total price cannot be obtained by reading a band and multiplying. Our own stock is one stone and is described separately below.

Why the Star Itself Is Not a Priced Grade Here

Most price guides for this material price it on the quality of the star. This one does not, and the reason is worth stating plainly.

The trade does price star stones on the phenomenon, and that much is not in dispute. What does not exist is any published laboratory grading of it. GIA states that it "doesn't grade or provide quality analysis for sapphire or other colored stones." The Laboratory Manual Harmonisation Committee, whose information sheets standardize report wording across the major laboratories, publishes none that covers asterism. CIBJO defines the category and stops there. So a description of how a particular star looks is the seller's own opinion — ours included — and no report can be produced to substantiate it.

The bands above are built instead on the three things a report or an invoice actually records: body color, carat weight, and what documentation comes with the stone. The star is the reason the stone exists. It is simply not something any laboratory will grade for you.

What You Actually Get at Each Budget

Under $100 per carat means a dark or very pale greyish body and usually no laboratory report at all — recognizably blue star sapphire, and priced accordingly.

Between $100 and $300 per carat, more of the blue reads through the grey. Documentation at this level is inconsistent, and worth asking about before you buy.

Between $300 and $800 per carat, the body color is clearly blue rather than grey, and a report from a recognized laboratory becomes the normal expectation rather than a bonus. Our own stone's per-carat figure falls in this band: $4,040 ÷ 8.09 ct = $499.38 per carat. That is arithmetic about a price, not a position on a quality scale.

Above $800 per carat you are paying for an even, saturated blue and a full report from a major laboratory — frequently one that carries a geographic origin opinion as well.

Carat Weight and Total Price

Per-carat price and total price are different numbers and it is easy to conflate them. Our 8.09 ct stone is $4,040 in total and $499.38 per carat; a 2 ct stone at the same per-carat level would come to just under $1,000. The per-carat figure is what lets you compare stones of different weights; the total is what you pay.

We have not published a size-by-band breakdown, because we have no source for one. Anyone who tells you blue star sapphire costs a specific multiple more per carat at 8 ct than at 3 ct is estimating, and so would we be.

Laboratory Reports

Laboratory-grown star corundum is common in the market and is not always easy to separate from natural material by eye, so a report earns its keep here more than on many stones. What a report does is identify the material, state whether it is natural or laboratory-grown, and record detectable treatment indications. Where the stone came from is a different question, answered by a different service.

Our stone is accompanied by GIA Sapphire Origin Report #2233980218, which places its geographic origin in Sri Lanka. GIA prints its own caveat beside that finding, and we would rather quote it than paraphrase it: "Any statement on geographic origin is an expert opinion based on a collection of observations and analytical data." The Laboratory Manual Harmonisation Committee makes the same point about reports generally — "All findings described in the report are opinions expressed by the laboratory." Those are opinions reached by qualified examiners, and that is exactly how we present them.

Origin is also not a quality grade, which is why it does not appear as a column in the table above. Where a stone was formed and how it looks are two separate findings, and pricing one as though it were the other is a habit worth breaking. See our natural star sapphire identification guide.

Frequently Asked Questions

How much does a blue star sapphire cost?

Blue star sapphire is commonly offered somewhere between about $30 and $3,000 per carat, and where a given stone falls depends on its body color, its carat weight, and what documentation comes with it. Those figures are an approximate market orientation rather than measured data. Our own stock is one stone: 8.09 ct at $4,040 in total, which works out at $499.38 per carat.

Is star quality graded by a laboratory?

No. GIA states that it "doesn't grade or provide quality analysis for sapphire or other colored stones," and the Laboratory Manual Harmonisation Committee, whose information sheets standardize report wording across the major laboratories, publishes none that covers asterism. A report will record that a stone displays the phenomenon; it will not rate it. So any description of how a particular star looks is the seller's own opinion, ours included, which is why we would rather send you video of the stone than hand you an adjective.

How many blue star sapphires do you have in stock?

One. An 8.09 ct blue star sapphire at $4,040, or $499.38 per carat, accompanied by GIA Sapphire Origin Report #2233980218, which places its geographic origin in Sri Lanka. One stone is not a price range and we have not presented it as one.

Shop Our Blue Star Sapphire

One stone, currently in stock: our 8.09 ct natural unheated blue star sapphire from Sri Lanka, $4,040 in total and $499.38 per carat, accompanied by GIA Sapphire Origin Report #2233980218. We can send video of the stone before you buy.

Explore Further

• Star Sapphire — The Complete Buyer's Guide
• Pink Star Sapphire Price Guide
• Purple & Violet Star Sapphire Price Guide
• Star Sapphire vs. Regular Sapphire — What's the Difference?
• How to Tell If a Star Sapphire Is Natural

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; $60 flat elsewhere, free over $499. 14-day returns on every order.