Natural Ametrine · 11.14 ct · Octagon · Bolivia · Unheated

This natural Ametrine weighs 11.14 carats and is fashioned in an elegant octagonal emerald cut, presenting a particularly attractive and well-balanced combination of natural purple and yellow colour zoning.

Measuring approximately 15.9 × 10.1 × 8.5 mm, the gemstone has an elongated geometric outline with substantial depth and a strong face-up presence. The broad table and structured faceting provide a clear view of the internal colour distribution while supporting an elegant, architectural appearance.

The gemstone displays a well-balanced division between purple and yellow, allowing both characteristic Ametrine colour zones to remain clearly visible when viewed face-up. The purple Amethyst-type area and yellow Citrine-type area interact attractively across the facet structure, with occasional pinkish and golden reflections appearing as the gemstone moves under changing illumination.

Ametrine is a naturally bicoloured variety of Quartz (SiO₂) in which Amethyst-type purple and Citrine-type yellow colour zones occur together within a single crystal. The quality of faceted Ametrine depends not only on colour saturation, but also on the positioning, contrast and visual balance of these natural growth zones.

This specimen shows particularly successful colour orientation. Rather than one colour strongly dominating the face-up appearance, the purple and yellow zones are distributed in a visually balanced manner, making the natural bicolour structure an important part of the finished design.

The gemstone is transparent and presents a clarity comparable to approximately VVS1, with only minute natural inclusions or subtle internal growth characteristics expected under magnification. This very clean internal appearance allows the colour zoning and step-style reflections to remain clearly visible.

The octagonal emerald-style faceting emphasises the geometry and natural zoning of the material. Good to very good cutting quality, Good symmetry and Very Good polish contribute to a refined surface presentation and effective internal reflections while preserving the gemstone’s substantial size.

Its vitreous luster is enhanced by the high-quality polish, while the combination of step-like reflections and contrasting purple and yellow areas gives the stone a distinctive visual character without relying on an artificial optical effect.

This specimen is recorded as unheated, with its purple and yellow colour zoning presented in its naturally observed state without documented heat enhancement.

The gemstone originates from Bolivia, the classic and most important commercial source of naturally occurring gem-quality Ametrine.

With its substantial 11.14 ct weight, very clean VVS-level appearance and notably balanced purple-and-yellow zoning, this natural Ametrine offers an excellent combination of colour contrast, transparency and geometric refinement. The octagonal emerald cut provides an elegant framework for the natural bicolour structure, making this an appealing gemstone for a distinctive custom jewellery design or a carefully selected collection.