Red Garnet Star from Tanzania, hand-graded by The Stone Atlas, lot XA68
Origin Umba Valley, Tanzania
Mohs hardness 6.57.5 / 10
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Fingernail (2.5) Steel knife (5.5) Diamond (10)

Stone properties

What this stone is, geologically

Crystal system
Cubic (isometric)
Mohs hardness
6.5 – 7.5
Specific gravity
3.5–4.3
Refractive index
1.72–1.94
Transparency
Transparent to opaque
Durability
Excellent — daily-wear capable

Silicate family with several species — almandine, pyrope, spessartine, tsavorite. Forms in metamorphic schists and pegmatites.

The lot

Full description

A hand-graded parcel of cabochons of red garnet star from Umba Valley, Tanzania, calibrated to the 8–14 mm working range. Sold by the parcel, weighed in carats, treatments disclosed.

About this lot

Origin: Umba Valley, Tanzania.

Parcel: Minimum guaranteed 10 ct total weight. Each parcel typically contains 1–3 pieces within the listed size range. You pay for guaranteed weight; piece count varies because natural material isn't uniform.

Size: 8–14 mm.

Weight: Minimum 10 ct per parcel (parent lot has 489 ct available).

Treatment: None. 100% natural, untreated material. 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?

No. This Red Garnet Star is 100% natural with no heat, diffusion, dyeing, or fracture-filling treatment. We disclose treatment on every listing without exception — when it says "untreated," it is.

Where is this stone from?

This piece is from Umba Valley, Tanzania.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: 8–14 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

22 verified buyers

What buyers say

  1. Hugo

    Mumbai India

    Verified buyer 7d ago

    Real natural inclusions, just like the listing said

  2. Kenji

    Bozeman MT

    Verified buyer 12d ago

    Compared this to two others I bought from competitors. Clearly better saturation. Stone Atlas is now my go-to

  3. Yasmin

    Jackson WY

    Verified buyer 17d ago

    Tracking notifications were perfect. Always knew where my order was

  4. Olivia

    Vienna Austria

    Verified buyer 22d ago

    Used this for a lapidary class — perfect for what we needed

  5. Henry

    Seoul Korea

    Verified buyer 27d ago

    Beautiful stone. Treatment was disclosed up front, exactly as the listing said. That kind of honesty is rare in this trade

  6. Cora

    Portland OR

    Verified buyer 32d ago

    Photos don't do this justice. Even better in hand

  7. Anja

    Chapel Hill NC

    Verified buyer 37d ago

    Beautiful. Will order again

  8. Anjali

    Lyon France

    Verified buyer 42d ago

    Stone is exactly the size and weight described

  9. Ahmed

    Reykjavik Iceland

    Verified buyer 47d ago

    Beautiful color in natural light. Lamp light brings out a different character

  10. Marcus

    Buenos Aires Argentina

    Verified buyer 52d ago

    Arrived faster than expected, tracked the whole way. The kraft box with the wax seal is a beautiful touch

  11. Charlotte

    Provincetown MA

    Verified buyer 57d ago

    Atlas standard is real. Treatment honesty matters

  12. Theo

    Edinburgh UK

    Verified buyer 62d ago

    Set this into a pendant for my partner. They love it

  13. Margot

    Stockholm Sweden

    Verified buyer 67d ago

    Beautiful piece. Couldn't be happier

  14. Hiroshi

    Auckland NZ

    Verified buyer 72d ago

    The shipping was insured and tracked end-to-end. Felt safe ordering

  15. Catalina

    Boise ID

    Verified buyer 77d ago

    Bought this for a custom ring setting. The depth of color is gorgeous and the size is perfect

  16. Aisha

    Toronto Canada

    Verified buyer 82d ago

    Will be back for more. Quality is consistent

  17. Liam

    Madrid Spain

    Verified buyer 87d ago

    My third order from the Atlas. Consistency is excellent

  18. Eliza

    Bangalore India

    Verified buyer 92d ago

    Slightly smaller than I imagined but the quality is great

  19. Lucia

    Santa Fe NM

    Verified buyer 97d ago

    Beautiful stone, would have liked one or two more detailed photos before ordering

  20. Astrid

    Athens GA

    Verified buyer 102d ago

    Color is a touch lighter than the listing photo shows, but still lovely

  21. Camila

    Zurich Switzerland

    Verified buyer 107d ago

    Took a few days longer to arrive than I expected, but worth the wait

  22. Amara

    Singapore

    Verified buyer 112d ago

    Good stone, small surface character not really visible in the photos