BICOLOUR SAPPHIRES

A bicolour sapphire is a sapphire that displays two distinct colours within a single stone. This characteristic stems from chemical variations during crystallisation. The stone shows clearly separated colour zones or soft transitions between hues. Every bicolour sapphire is therefore unique. The most sought-after combinations pair blue with yellow, pink with orange, or blue with violet.

A sapphire's colour depends on the trace elements present in its crystal structure. As the crystal grows, these elements can vary. The stone then develops zones of differing composition, each producing its own hue. Iron yields yellow, chromium yields pink, and iron combined with titanium yields blue. The layering of these zones accounts for the characteristic bicolour effect.

Several combinations occur in bicolour sapphires. Blue and yellow is one of the most prized for its vivid contrast. Pink and orange echoes the tones of a padparadscha sapphire, without meeting its strict criteria. Blue and violet creates mysterious, deep gradients. Green and blue evokes the nuances of a teal sapphire. More rarely, tricolour sapphires with three distinct hues can be found.

Bicolour sapphires originate primarily from the same sources as other sapphires. Sri Lanka remains the leading origin for the purest and most contrasted stones. Madagascar has established itself as the world's second major source, offering a wide range of combinations. Tanzania and Australia round out the supply. At Bonnot Paris, we source our bicolour sapphires directly through our office in Sri Lanka.

The price of a bicolour sapphire depends on the colour combination, clarity, and contrast between zones. Expect €500 to €1,500 per carat for average quality (1 carat). Stones with sharply defined, well-contrasted colour zones reach €2,000 to €5,000 per carat. Exceptional bicolour sapphires with vivid, clearly delineated colours can exceed €8,000 per carat. The unique nature of each stone has a significant influence on the final price.

Yes, bicolour sapphires are among the least common varieties on the market. Nature rarely produces these precise, well-defined chromatic zones. Most sapphires display a uniform dominant colour. True bicolour stones with marked contrast account for less than 5% of global production. This rarity explains the growing interest from collectors and enthusiasts of distinctive gemstones.

Yes, it is a bold and singular choice. A bicolour sapphire offers the same hardness of 9 on the Mohs scale as other sapphires. It withstands everyday wear perfectly and requires no protective setting. Its dual hue evokes union, duality and complementarity — a powerful symbol for a marriage proposal. It is also a choice that departs radically from classic conventions. As every stone is unique, your ring will be too.

The choice of cut is essential to doing justice to a bicolour sapphire. The rectangular emerald cut highlights chromatic zoning particularly well. The cushion cut delivers a softer, more romantic result. The oval cut brings out the depth of both hues. For the setting, favour a mount that does not interfere with the reading of the colours. White gold or platinum remain the most neutral choices. Yellow or rose gold creates a chromatic dialogue with the stone.