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NATURAL IOLITE JEWELLERY
Traced back to ancient history as the legendary Scandinavian “Sunstone”, natural iolite is renowned for its captivating twilight blue depth and striking pleochroism. Shifting gracefully from deep indigo to soft violet and watery slate, iolite embodies the fleeting colours of the evening horizon in an authentic, untreated gemstone.
Unlike widely available blue gemstones, such as London Blue, Swiss Blue, or Sky Blue topaz, which rely on artificial radiation and heat treatments to produce their blue hues, iolite is 100% natural and untreated. Mined directly from the earth in its authentic colour, it offers a rare, unadulterated beauty that reflects nature’s artistry without human intervention.
Colour spectrum
Indigo, violet, slate
Pictured: Octagonal Iolite Necklace
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Mg₂Al₄Si₅O₁₈
Cordierite · Magnesium aluminium silicate
A magnesium aluminium silicate mineral (cordierite), valued for its deep twilight hues and exceptional optical transparency.
7 to 7.5
on the Mohs scale
Rating 7 to 7.5 on the Mohs Hardness Scale, iolite provides reliable scratch resistance for daily fine jewellery when set thoughtfully to protect its directional cleavage.
Exhibiting remarkable trichroism, a single iolite gemstone reveals shifting shades of violet blue, pale blue, and honey yellow depending on the angle of light, completely free from heat treatment or artificial enhancement.
While blue topaz is widely popular in commercial jewellery across various shade grades, almost all varieties are produced through artificial treatment processes.
| Feature | Only at UgemsNatural Iolite | Treated Blue Topaz (London, Swiss & Sky Blue) |
|---|---|---|
| Origin & Authenticity | 100% Natural & UntreatedMined directly from the earth; heat treatment is ineffective, ensuring every stone is unenhanced. | Routinely Irradiated & HeatedCreated by artificially irradiating and heat treating colourless topaz to produce blue shades. |
| Mohs Hardness | 7 to 7.5 / 10Good scratch resistance; features distinct directional cleavage requiring mindful setting design. | 8 / 10High scratch resistance and durability suitable for daily wear. |
| Refractive Index (Lustre) | 1.54 to 1.55Soft, velvety glow with deep light absorption and watery transparency. | 1.61 to 1.64Bright, crisp reflectivity with high vitreous surface lustre. |
| Dispersion & Optical Effect | 0.017 (Strong Trichroism)Shifts visibly between violet blue, pale blue, and yellowish hues as the stone turns in light. | 0.014 (Weak Pleochroism)Displays static, uniform colour throughout the stone with minimal shift across angles. |
| Visual Character | Twilight & ShiftingA captivating indigo violet shade that changes personality in motion and varied lighting. | Uniform Engineered Blues
|
| Ugems co. Positioning | Exclusively FeaturedChosen for its guaranteed 100% natural state, magical pleochroism, and authentic earth born heritage. | Not Offered |
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