4.55 Ct. Blue Tanzanite from Tanzania

This listing presents a single, transparent blue tanzanite, oval shape, weighing 4.55 carat. The gem measures 12.03 x 8.85 x 6.16 mm, and exhibits a mixed brilliant cut that combines pavilion faceting designed to optimize brightness, with crown faceting that emphasizes color depth. The stone displays medium color intensity, an eye clean clarity grade, evaluated at eye level, and an excellent polish that enhances surface luster and optics. The material has been heat treated, a widely accepted and stable enhancement method applied to tanzanite to reveal the characteristic violet to blue hues. Origin is Tanzania, the only known commercial source for gem quality tanzanite, which contributes to the gemological and market context of this piece.

From a gemological perspective, the 4.55 carat weight of this tanzanite is a defining attribute, both visually and commercially. Carat weight quantifies mass, yet it also directly influences perceived size, presence on the finger, and light performance when set. At 4.55 carat, this oval tanzanite occupies a dimensional range in which crown height and pavilion depth remain balanced, preserving the mixed brilliant cut proportions evident in the provided measurements. The 12.03 mm length and 8.85 mm width create an elegant elongated silhouette, while the 6.16 mm depth contributes to a substantial table and reflective pavilion surfaces. The eye clean clarity at this scale ensures that the visible face up presentation is free of inclusions that could interrupt light return, a critical factor for larger gems where internal features are more likely to affect appearance.

Weight and rarity are interrelated for tanzanite, and the 4.55 carat classification places this stone into a scarcity tier relative to smaller sizes. Tanzanite is mined in a single alluvial and primary deposit zone in northern Tanzania, where the geology yields gem bearing material in limited volumes and with variable crystal sizes. Larger, well formed crystals that can be cut to produce faceted stones above four carat occur far less frequently than smaller specimens. As a result, market dynamics reflect a stepped premium as carat weight increases, with per carat values rising significantly for stones that combine size with desirable color, clarity, and cut. In practical terms, a tanzanite like this one benefits from the convergence of weight and quality, since the 4.55 carat mass is sufficient to command a higher per carat valuation than common 1.00 to 2.00 carat stones, while the mixed brilliant cut and eye clean clarity preserve optical quality rather than sacrificing it for weight retention.

Cutting and treatment choices influence how weight translates to value, and this specimen demonstrates a balance between material retention and optical optimization. The cutter has retained substantial weight while executing a mixed brilliant scheme that promotes scintillation and color zoning control. Heat treatment, applied to bring out the desirable blue violet tones typical of tanzanite, is stable and customary in the trade, and it allows for more consistent market expectations regarding color. The medium color intensity of this stone situates it within a range that is both wearable and collectible, offering a visually appealing saturation without the tradeoff of overly dark tone that can mute brilliance. The excellent polish supports premium light return and a reflective surface that compliments the table and facets created in the mixed brilliant design. Together, these attributes support the premium associated with this weight class.

For clients and designers considering settings, a 4.55 carat oval tanzanite of these dimensions presents multiple possibilities that maintain structural integrity and aesthetic balance. The length and width suit a solitaire mounting for a ring with proportional band width, or a three stone composition where the center weight is balanced by side stones that enhance perceived size and color. In pendants and brooches, the substantial depth and mixed brilliant cut maximize light performance when suspended freely. From a care perspective, the stone should be protected from hard knocks and extreme thermal shock, and routine cleaning with warm soapy water and a soft brush will preserve polish and brilliance. Documentation of heat treatment and origin is an important component of provenance, and The Natural Gemstone Company provides detailed disclosure as part of our standard listing information. This 4.55 carat blue tanzanite represents a measured intersection of weight, clarity, cut, and origin, offering a rare and tangible example of the material and market characteristics that distinguish higher weight tanzanite specimens.