Chrome Tremolite from Tanzania, hand-graded by The Stone Atlas, lot XA58
Origin Merelani Hills, Tanzania
Mohs hardness 56 / 10
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Fingernail (2.5) Steel knife (5.5) Diamond (10)

Stone properties

What this stone is, geologically

Crystal system
Monoclinic (amphibole)
Mohs hardness
5 – 6
Specific gravity
2.9–3.2
Refractive index
1.599–1.637
Transparency
Translucent to opaque
Durability
Moderate — protected mounting preferred

Calcium magnesium iron silicate from metamorphic environments. Chrome substitution gives the saturated green.

The lot

Full description

A hand-graded 5-piece lot of cabochons of chrome tremolite from Merelani Hills, Tanzania, calibrated to the 31–40 mm working range. Sold as one curated lot, weighed in carats, treatments disclosed.

About this lot

Origin: Merelani Hills, Tanzania.

Lot: Curated 5-piece selection sold as a single unit. Total weight approximately 184 ct, hand-photographed exactly as shipped — you receive the stones in the photograph, no substitution.

Size: 31–40 mm.

Weight: 184 ct total (entire lot).

Treatment: None. 100% natural, untreated material. Disclosed on every listing — that's the Atlas standard.

Suggested use

Lapidary work, custom jewellery settings, or studio display.

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 Chrome Tremolite 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 Merelani Hills, 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: 31–40 mm. Listed weight: 184 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.

4.8 out of 5

17 verified buyers

What buyers say

  1. Catalina

    Berkeley CA

    Verified buyer 7d ago

    Real natural inclusions, just like the listing said

  2. Aisha

    Berlin Germany

    Verified buyer 12d ago

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

  3. Liam

    Tokyo Japan

    Verified buyer 17d ago

    Tracking notifications were perfect. Always knew where my order was

  4. Eliza

    Cape Town South Africa

    Verified buyer 22d ago

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

  5. Lucia

    Carmel CA

    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. Astrid

    Dublin Ireland

    Verified buyer 32d ago

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

  7. Camila

    Oslo Norway

    Verified buyer 37d ago

    Beautiful. Will order again

  8. Amara

    Tel Aviv Israel

    Verified buyer 42d ago

    Stone is exactly the size and weight described

  9. Sophia

    Sedona AZ

    Verified buyer 47d ago

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

  10. Caleb

    Montréal Canada

    Verified buyer 52d ago

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

  11. Stefan

    Amsterdam Netherlands

    Verified buyer 57d ago

    Atlas standard is real. Treatment honesty matters

  12. Léa

    Sydney Australia

    Verified buyer 62d ago

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

  13. Hana

    Boulder CO

    Verified buyer 67d ago

    Beautiful piece. Couldn't be happier

  14. Khalid

    Lexington KY

    Verified buyer 72d ago

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

  15. James

    Florence Italy

    Verified buyer 77d ago

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

  16. Harper

    Taipei Taiwan

    Verified buyer 82d ago

    Will be back for more. Quality is consistent

  17. Levi

    Asheville NC

    Verified buyer 87d ago

    My third order from the Atlas. Consistency is excellent