
Mozambique Ruby - 4.09 ct, Untreated, GRS Certified
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This 4.09 carat natural pinkish-red ruby represents a rare intersection of size, integrity, and documented origin. Fashioned in an oval shape with a modified brilliant/step cut (9.61 × 8.13 × 5.70 mm), the stone displays strong internal life and saturation while preserving excellent structural balance.
With VS clarity, this ruby belongs to the upper tier of investment-grade material for unheated stones above four carats. Minor internal features are present, consistent with its natural formation and clearly observable under magnification. These characteristics form a delicate internal jardin — a gemological fingerprint that confirms both its earth-mined origin and the absence of thermal enhancement.
Gemological testing by GRS Gemresearch Swisslab reports “No indication of thermal treatment”, verified through FTIR analysis. In the context of high-value ruby collecting, the absence of heat treatment is a defining criterion of long-term value, often outweighing absolute visual purity. Stones of comparable size without internal features typically indicate either aggressive enhancement or synthetic origin and occupy a fundamentally different market category.
The stated Mozambique origin places this ruby among the most recognized modern sources of fine-quality, unheated material. Over the past decade, Mozambique has established itself as one of the few origins capable of producing rubies above four carats that meet contemporary investment standards and laboratory scrutiny.
This ruby was selected not as a retail gemstone, but as a defensible asset — one that withstands professional examination, institutional verification, and market comparison. While perfectly suitable for the most exclusive bespoke jewelry commissions, its primary value lies in its rarity, documentation, and gemological integrity.
Investment Rationale
- Unheated natural ruby above 4.00 ct
- VS clarity within investment-standard parameters
- GRS certification with FTIR testing
- Recognized Mozambique origin
- Scarcity-driven value profile in the global ruby market
Gemological Disclosure
Nature leaves its signature in every unheated ruby. The minor internal features present in this stone are part of its unique identity and do not compromise its brilliance or structural stability. On the contrary, they serve as tangible proof of its natural journey and untreated state.
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Documentation & Verification
Every gemstone is supplied with the documentation stated in the product specification. This may include an independent laboratory certificate or a Sosna Gems Colored Stone Report.
Additional or alternative independent laboratory certification can be arranged upon request for eligible gemstones.

Learn about bespoke jewelry
Every bespoke piece begins with a gemstone. Selected gemstones from our collection can be transformed into individually designed jewelry, created around the proportions, character and intended use of each stone.
Every design is developed in consultation with our gemologists and goldsmiths, ensuring that the finished piece complements both the gemstone and your preferences.
Gemological overview
Technical and gemological information about this gemstone variety.





