4.63 Ct. Violetish Blue Tanzanite from Tanzania

This transparent violetish blue tanzanite from Tanzania, offered by The Natural Gemstone Company, is precisely calibrated at 4.63 carats, with dimensions of 12.00 x 8.01 x 5.38 mm. The stone has an emerald cut executed as a classical step cut, featuring broad, parallel faceting on the crown and pavilion that emphasize the gem's internal color zoning and pleochroic behavior. The length to width ratio of approximately 1.50 yields a balanced, elongated profile, while the measured depth of 5.38 mm produces a depth percentage of approximately 53.7 percent relative to the average of length and width, a range that supports both strong face up color and retention of weight. Clarity is reported as very slightly included, evaluated at eye level, which in combination with the transparent material and excellent polish allows clean facet junctions and crisp light return. The gem displays intense color saturation in the violetish blue range typical of well treated tanzanite, and the documented enhancement is heat treatment, which stabilizes and intensifies the blue to violet shift, resulting in rich, consistent color across the table and steps.

From a valuation and rarity perspective the 4.63 carat weight is the defining attribute that elevates this tanzanite beyond common sizes, because tanzanite supply diminishes exponentially at heavier weights and high quality material above four carats with intense color is comparatively scarce. The emerald cut conserves weight by minimizing pavilion removal, which is significant when cutters are balancing color retention against inclusion removal, therefore a 4.63 carat finished stone indicates efficient rough conversion and strong rough quality. Market premiums for tanzanite typically escalate with size and with color intensity, so the combination of intense violetish blue hue, very slightly included clarity at eye level, and an excellent polish commands a materially higher per carat value than smaller or more included examples. For makers and connoisseurs who demand technical precision, the step faceting and proportion set of this gem optimize color saturation and windowing control, making it particularly suitable as a center stone in substantial rings or bespoke jewelry, where the weight contributes both to visual impact and to a higher asset value.