Natural Ametrine · 11.08 ct · Octagon · Emerald Cut · Unheated

This natural Ametrine weighs 11.08 carats and is fashioned in an elegant octagonal cut, presenting a particularly attractive and well-balanced division between its natural purple and yellow colour zones.

The gemstone displays a combination of purple Amethyst-type colour and yellow Citrine-type colour within a single natural Quartz crystal. Viewed face-up, the two colour zones are separated by a clearly defined natural colour boundary, creating a strong and visually balanced bicolour presentation.

Unlike gemstones assembled from separate materials, Ametrine is a single variety of Quartz (SiO₂) in which purple and yellow colour zones developed naturally within the same crystal. This natural zoning is the defining gemmological characteristic of Ametrine and is particularly attractive when the cutter is able to orient the material so that both colours remain clearly visible in the finished gemstone.

In this specimen, the colour division is especially successful. The purple zone shows good colour quality, while the yellow zone displays very good colour quality, producing an attractive contrast across the face of the stone. The relatively balanced distribution allows both colours to contribute meaningfully to the overall appearance rather than one zone visually dominating the gemstone.

The material is highly transparent and presents an approximately VVS clarity profile, with only minute natural inclusions or subtle growth features expected to be visible under magnification. This very good clarity allows the natural bicolour structure to remain clearly visible and contributes strongly to brightness and internal light transmission.

The octagonal faceting has been oriented effectively around the natural colour zoning. Good to very good cutting quality and good to very good symmetry provide a balanced geometric presentation, while very good polish enhances the characteristic vitreous luster of Quartz.

The relatively broad face-up presentation and clearly defined colour boundary allow the purple and yellow sections to interact with the facet pattern independently, producing alternating reflections from both colour zones as the gemstone is viewed from different angles.

There are no indications of heating and no indications of any other treatment. The observed purple and yellow colour zoning is therefore presented in its naturally documented state without indications of enhancement.

This specimen is recorded as originating from Bolivia, the classic and most important commercial source associated with naturally occurring gem-quality Ametrine.

With its 11.08 ct weight, very good clarity and particularly attractive division between purple and yellow, this natural Ametrine offers a refined expression of the gemstone’s characteristic bicolour structure. The clearly defined colour zoning, strong transparency and well-executed octagonal faceting make it an appealing choice for a distinctive custom jewellery design or a carefully selected gemstone collection.