Unheated Tanzanite Crystal Pleochroic Mineral Specimen, Merelani Hills, Tanzania, 56.5ct

What I love about this Tanzanite is just how much its appearance changes as you turn it in the light. From one angle, you’re looking at beautiful violet-purple and deep blue, but rotate it slightly and these wonderful golden-yellow tones begin to appear, along with occasional warm, almost coppery reflections. It’s a fantastic example of the pronounced pleochroism found in natural, unheated Tanzanite, and something that really needs to be seen in motion to appreciate properly. This substantial 56.5-carat (11.3g) crystal comes from the famous Merelani Hills of Tanzania, and its contrasting natural colours are what immediately drew me to it.

The crystal itself has an impressive prismatic formation, with broad, glossy faces and fine vertical growth striations that are particularly noticeable when the light catches them. There are some lovely transparent areas where you can look into the crystal and see the natural inclusions, internal fractures and colour zoning. The upper termination is irregular, with a mixture of well-preserved growth faces and more uneven surfaces, all contributing to its individual character. For me, it’s the combination of that striking colour change and the substantial natural crystal formation that makes this such an interesting collector specimen. It’s a wonderful example of why unheated Tanzanite can be so fascinating beyond the world of cut gemstones.

Specifications

• Mineral: Tanzanite (Zoisite)
• Locality: Merelani Hills, Simanjiro District, Manyara Region, Tanzania
• Weight: 11.3g (56.5 carats)
• Measures: 3.1 x 1.9 x 1.3cm (approx.)
• Colour: Violet-purple, blue-violet and golden-yellow, with occasional coppery reflections
• Optical Properties: Pronounced pleochroism (trichroism)
• Treatment: Natural, unheated
• Crystal Formation: Prismatic crystal with longitudinal growth striations and an irregular upper termination
• Transparency: Translucent to transparent in areas
• Lustre: Vitreous
• Condition: Preserved natural growth faces, visible internal fractures and inclusions, with irregular upper surfaces

Metaphysical Properties

Tanzanite is traditionally associated with intuition, communication, spiritual awareness and personal transformation. Its violet and blue colours are believed to encourage clarity of thought, emotional balance and self-expression. These associations come from traditional crystal beliefs and are not scientifically proven.