5.90 Ct. Tanzanite from Tanzania

This listing presents a single transparent 5.90 carat emerald cut violet tanzanite, with precise dimensions of 10.94 x 8.19 x 7.14 mm, cut and finished by expert hands and offered by The Natural Gemstone Company. The stone is an emerald cut, which in practical terms means a step cut with broad rectangular crown and pavilion facets arranged in parallel tiers, a prominent table, and truncated corners that focus color rather than microscopic scintillation. The cutting proportions yield a depth ratio of approximately 75 percent, a deliberate choice that sacrifices some table brightness in favor of intensified color and perceived saturation when viewed face up. The clarity is graded as eye clean at normal viewing distances, which confirms the cutter selected material with minimal internal interference so that the step facets can present large planes of uninterrupted color. The polish is excellent with crisp facet junctions and mirrorlike surfaces, and the piece has been heat treated to achieve and stabilize the vivid violet color. The gem is from Tanzania, and the heat treatment described is a standard, stable enhancement widely accepted in the trade to convert natural brownish zoisite into the vivid violet blue characteristic of high quality tanzanite.

From an optical and gemological perspective, this tanzanite stands apart from more common gemstones in several measurable ways. Tanzanite has a refractive index in the range of approximately 1.69 to 1.70, and dispersion around 0.014, values that are noticeably lower than diamond and somewhat lower than corundum. By pure numbers this means tanzanite will not display the same level of fire or the extreme sparkle that a diamond presents, however numerical indices do not tell the whole story. Tanzanite is strongly trichroic, exhibiting distinct color responses along its three crystallographic axes, typically showing intense violet on one axis and deeper blue or burgundy on the others. The emerald cut on this stone emphasizes those broad color planes, creating bold flashes of saturated violet rather than the pinfire scintillation you expect from a brilliant cut sapphire or diamond. Compared to a sapphire of similar weight, which relies more on high refractive index and numerous small facets to produce sparkle, this tanzanite provides a different optical pleasure, namely deep, velvety color saturation and large, clean flashes of hue as the stone is oriented under light. Against amethyst and other purple stones commonly seen in jewelry, this piece is significantly more vibrant because of both the higher clarity and the vivid intensity achieved by heat treatment combined with the cutter s decision to retain substantial depth.

Craftsmanship and practical handling details are important for buyers who appreciate the technical nuances. The step cutting technique used on this emerald shape requires exacting symmetry and precision polishing to ensure that each tier of facets aligns to create controlled light return, and the excellent polish indicates that diamond laps were used to achieve tight facet junctions and optical flatness. The eye clean clarity grade ensures that the large facets read as uninterrupted color fields, which is exactly what a step cut is intended to showcase, and the decision to maintain a deeper profile intensifies color in settings where less depth would produce a washed out face up tone. Heat treatment is disclosed because it is a stable, industry accepted enhancement that produces the vivid violet intensity buyers seek, and it does not materially affect the structural integrity of the gem when cared for appropriately. Tanzanite has a Mohs hardness in the region of approximately 6.5 to 7, therefore we advise protective settings for rings intended for daily wear, or consideration for pendants and earrings when maximum durability is desired. For mountings we recommend bezel or substantial prong settings that protect the corners, given the emerald cut geometry.

In summary, this 5.90 carat emerald cut violet tanzanite from Tanzania offers an interplay of technical factors that serious buyers value, namely precise step cutting, eye clean clarity, a deliberate depth ratio to maximize face up color, and excellent polish, all combined with stable heat enhancement to ensure vivid color. Its optical character will differ from diamonds and sapphires, because it trades extreme dispersion for large, saturated color planes and pronounced pleochroism, making it a statement stone for clients who appreciate color driven brilliance rather than pure fire. The Natural Gemstone Company stands behind the grading details provided, and we welcome inquiries for additional photographic angles, specific light performance demonstrations, or recommendations for custom setting designs that will optimize the optical and physical performance of this exceptional tanzanite.