Natural bi colour sapphire weighing 3.70 carats, featuring a round cut, blue and yellow colour zoning, SI clarity and heat treatment. Offered as a loose gemstone for custom engagement rings, pendants and bespoke jewellery designs, with certification from an authorised gemmologist.
This natural bi colour sapphire displays a striking combination of blue and yellow within a single gemstone. Weighing 3.70 carats and cut in a classic round shape, it is supplied as a loose sapphire, allowing complete flexibility for custom jewellery designs including engagement rings, pendants and statement pieces.
Quick Summary
- Natural bi colour sapphire
- Weight: 3.70 carats
- Round cut loose gemstone
- Colour: Blue and Yellow
- Clarity: SI
- Treatment: Heat Treated
- Birthstone: September
- Certificate from an authorised gemmologist included
The round cut enhances brilliance and symmetry while showcasing the natural contrast between the blue and yellow colour zones. Bi colour sapphires are appreciated for their distinctive appearance, with each gemstone displaying its own individual colour distribution.
Sapphire belongs to the corundum family and ranks 9 on the Mohs hardness scale, making it suitable for jewellery intended for regular wear when professionally set. As the birthstone for September, sapphire has traditionally been associated with wisdom, loyalty and sincerity.
Gemstone Specifications
- Identification: Natural Sapphire
- Species: Natural Corundum
- Variety: Bi Colour Sapphire
- Shape & Cut: Round
- Clarity: SI
- Weight: 3.70 Carats
- Colour: Blue Yellow Bi Colour
- Measurements: 9.00 × 5.20 mm
- Treatment: Heat Treated
- Birthstone: September
Certification & Authenticity
This sapphire includes a certificate issued by an authorised gemmologist confirming its natural identity and disclosed treatment.
Seller Notes: Crystal and mineral inclusions are present. These internal characteristics are commonly found in natural sapphires and are consistent with natural gemstone formation.
Slight colour variation may be visible under different lighting conditions due to the natural colour composition of the gemstone.
Jewellery Applications
This listing is for a loose gemstone only and does not include a finished ring or jewellery setting.
Suitable applications include:
- Custom engagement rings
- Statement rings
- Pendants
- Custom fine jewellery
- Personalised jewellery projects
Custom jewellery services are available in yellow gold, white gold, rose gold, silver and platinum with optional diamond accents.
Why Choose a Bi Colour Sapphire?
Bi colour sapphires naturally display two colours within a single crystal, giving every gemstone a distinctive appearance. Their unique colour zoning makes them a popular choice for buyers seeking an alternative to traditional single-colour sapphires while maintaining the durability and timeless appeal associated with natural sapphire.
Explore Related Collections
Browse related collections and educational resources:
- Bi Colour, Teal & Blue Green Sapphire Collection
- All Loose Sapphire Gemstones
- Gemstone Education Articles
Shipping & Returns
Worldwide shipping is available with tracking and insurance included. Delivery times generally range from 7–12 business days depending on destination. Buyers are responsible for any applicable customs duties or import taxes.
Returns are accepted according to our published return policy, provided the gemstone is returned in its original condition within the applicable return period.
Frequently Asked Questions
Is this a natural bi colour sapphire?
Yes. This gemstone is a natural bi colour sapphire belonging to the corundum family.
Has this sapphire been treated?
Yes. This sapphire has undergone heat treatment, which is disclosed in the specifications and gemmological certificate.
Is this sold as a finished ring?
No. This listing is for a loose gemstone only. Custom jewellery settings are available separately.
Can this sapphire be used for an engagement ring?
Yes. Its durability, round cut and size make it suitable for custom engagement ring designs.
Why do bi colour sapphires display two colours?
Bi colour sapphires naturally develop multiple colours during crystal growth, creating distinctive colour zoning that makes each gemstone unique.
Important Information
- All gemstones offered are natural and earth-mined.
- Any treatment applied is disclosed within the product specifications.
- Natural gemstones may contain inclusions such as feathers, crystals, needles or colour zoning, which are normal characteristics of natural formation.
- Photographs are provided to represent the gemstone from multiple angles, although colour may vary slightly under different lighting conditions.
- Please contact us if you require additional photographs or assistance with a custom jewellery design.








