Just sold
·
Origin
Chanthaburi, Thailand
Mohs hardness
9
/ 10
12345678910
Fingernail (2.5)
Steel knife (5.5)
Diamond (10)
Stone properties
What this stone is, geologically
- Crystal system
- Trigonal (corundum)
- Mohs hardness
- 9
- Specific gravity
- 3.95–4.05
- Refractive index
- 1.762–1.778
- Transparency
- Transparent to translucent
- Durability
- Exceptional — second only to diamond
Aluminum oxide crystallized at high temperature in metamorphic and igneous environments. Asterism comes from oriented rutile inclusions.
The lot
Full description
A hand-graded parcel of cabochons of blue star sapphire from Chanthaburi, Thailand, calibrated to the 6–12 mm working range. Sold by the parcel, weighed in carats, treatments disclosed.
About this lot
Origin: Chanthaburi, Thailand.
Parcel: Minimum guaranteed 10 ct total weight. Each parcel typically contains 4–7 pieces within the listed size range. You pay for guaranteed weight; piece count varies because natural material isn't uniform.
Size: 6–12 mm.
Weight: Minimum 10 ct per parcel (parent lot has 541 ct available).
Size note: Wide size variance — stones range from 6 mm to 12 mm (2.0× spread). Expect a mix of sizes rather than uniform stones. Best for cutters, lapidary projects, or mixed-jewellery use; not ideal if you need matched pairs.
Treatment: Diffusion-treated (industry-standard for blue star sapphires from this region). Disclosed on every listing — that's the Atlas standard.
Suggested use
Setting in jewellery — ring bezels, pendant cabochons, statement earrings. Dome and polish are jewellery-ready.
The Stone Atlas standard
Hand-graded in our US studio. Treatments disclosed on every listing, no exceptions. Shipped insured from the US since 1995. Returns within 14 days if the stone in hand doesn't match the listing.
Shipping & returns
- Ships: from the US within 1–2 business days.
- Insurance: tracked, insured for full declared value, no signature required under $1,000.
- Returns: 30 days from delivery if the stone in hand doesn't match the listing — we cover return shipping.
Common questions
About this stone.
Is this stone treated?
Yes. The treatment for this Blue Star Sapphire is: Treated. We disclose treatment on every listing without exception — that's the Atlas standard.
Where is this stone from?
This piece is from Chanthaburi, Thailand.When we know the specific city or mine, we tag it on every listing. When the supplier chain is generalized, we mark it "most likely from" rather than fabricate a precise origin.
Can I see a GIA certificate?
Yes. GIA certification is available as a $95 add-on after checkout. Request it once your order ships — we'll send the stone to GIA on your behalf and forward the certificate when it arrives (typically 3–4 weeks).
What's your return policy?
Every stone comes with a 30-day inspection window. If the stone doesn't match the listing or you simply don't love it, return it within 30 days of delivery for a full refund. We cover return shipping. No restocking fees, no questions.
How long does shipping take?
Orders ship from the US within 1–2 business days. Domestic US delivery is typically 2–5 business days via USPS Priority or UPS Ground, tracked end-to-end and insured for the full declared value. International shipping is available at checkout.
Is the size in the listing exact?
Listed size for this piece: 6–12 mm. Listed weight: 10 ct ct. All sizes and weights are hand-measured. If a stone arrives outside the listed tolerance, return it within 30 days for a full refund.
Can I see this stone in different lighting before I buy?
Yes. Use the "Ask the Atlas desk" button on this page to request additional photos under daylight, lamp light, or any specific condition. We typically reply within one business day with photos attached.
What if I'm a jeweler — do you offer wholesale?
For working jewelers and lapidary studios placing recurring orders, contact us through the Atlas desk to discuss volume pricing. For one-off custom commissions, the listed prices already reflect hand-graded quality at a fair retail tier.
4.7 out of 5
18 verified buyers
What buyers say
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Noah
Bangkok Thailand
Real natural inclusions, just like the listing said
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Abigail
Burlington VT
Compared this to two others I bought from competitors. Clearly better saturation. Stone Atlas is now my go-to
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Henrik
Iowa City IA
Tracking notifications were perfect. Always knew where my order was
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Matteo
Rome Italy
Used this for a lapidary class — perfect for what we needed
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Rohan
Hong Kong
Beautiful stone. Treatment was disclosed up front, exactly as the listing said. That kind of honesty is rare in this trade
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Nour
Brooklyn NY
Photos don't do this justice. Even better in hand
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Mia
Berkeley CA
Beautiful. Will order again
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Owen
Berlin Germany
Stone is exactly the size and weight described
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Iris
Tokyo Japan
Beautiful color in natural light. Lamp light brings out a different character
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Niels
Cape Town South Africa
Arrived faster than expected, tracked the whole way. The kraft box with the wax seal is a beautiful touch
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Arjun
Carmel CA
Atlas standard is real. Treatment honesty matters
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Omar
Dublin Ireland
Set this into a pendant for my partner. They love it
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Daniel
Oslo Norway
Beautiful piece. Couldn't be happier
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Amelia
Tel Aviv Israel
The shipping was insured and tracked end-to-end. Felt safe ordering
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Asher
Sedona AZ
Bought this for a custom ring setting. The depth of color is gorgeous and the size is perfect
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Soren
Montréal Canada
Will be back for more. Quality is consistent
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Mei
Amsterdam Netherlands
My third order from the Atlas. Consistency is excellent
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Valentina
Sydney Australia
Worth every dollar. Real natural stone, no funny business
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