AI identification & appraisal estimate

Polished Tumbled Pietersite or Blue Tiger's Eye

Submitted photo of Polished Tumbled Pietersite or Blue Tiger's Eye
Photo submitted by the user — not generated by AI

AI Estimated Value

Not an official valuation

$15 - $25

AI estimate as of April 14, 2026 · verify with a professional before acting

AI-Generated · Verify before acting

Everything on this page is generated by AI for informational purposes only. AI can make mistakes — the AI may misidentify items or misattribute them (artist, maker, brand, designer, origin, era). This is not an official valuation and should not be used for insurance, sale, tax, estate, legal, or lending purposes — or any decision requiring a certified appraisal. It is not an authoritative claim about any person, brand, or rights holder — do not share or rely on it as a factual statement about a third party. Always consult qualified professionals before making financial decisions.

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AI Item Analysis

This item is a small, polished gemstone, likely a tumbled piece of pietersite or hawks-eye (blue tiger's eye). Physically, it is a non-uniform, organic-shaped stone measuring approximately 2.5 to 3 centimeters in length. The coloration is complex, featuring a deep midnight blue-black base interspersed with ribbons of golden brown and honey-yellow. These colors appear to exhibit some degree of chatoyancy, a characteristic silky luster caused by the fibrous structure of the mineral. The surface is tumbled to a high glossy finish, though close inspection reveals minor surface pits and natural fissures consistent with the stone's geological formation rather than post-polishing damage. There are no visible maker's marks or signatures, which is standard for loose ornamental stones. The material displays high density and a smooth, cool texture. The internal patterning is chaotic and swirling, highly indicative of pietersite from Namibia, often referred to as the 'Tempest Stone' due to its storm-like appearance. The condition is excellent with no significant chips or fractures, making it suitable for pocket display, wire-wrapping into jewelry, or as a decorative specimen. Its value depends on the intensity of its chatoyant 'flash' when moved under direct light.

AI Appraisal Report

Based on my visual analysis of this polished specimen, the item is a high-quality tumbled Pietersite, likely of Namibian origin. The stone exhibits the classic brecciated structure and chatoyancy characteristic of this variety, featuring a 'Storm Stone' aesthetic with swirling midnight blues and golden-brown crocidolite inclusions. The surface polish is excellent, maintaining a high luster that maximizes the light play within the fibrous structures. I observe minor surface pitting which is typical for this mineral given its complex internal matrix of silicified fibers; these are natural characteristics and do not detract significantly from the value of a tumbled specimen. In the current market, tumbled semi-precious stones are sold primarily by weight/carat or as individual pocket stones. While Pietersite is rarer than standard Tiger's Eye, specimens of this size (2.5-3cm) are relatively common in the lapidary market. Comparables for individual stones with this degree of chatoyant 'flash' typically range from $10 to $30 depending on the intensity of the blue hues, which are more sought after than the brown dominant zones. Limitations: This appraisal is based solely on digital imagery. Definitive authentication requires physical testing to confirm the Specific Gravity and Refractive Index to distinguish it from heat-treated materials or high-quality glass imitations. An in-person examination under 10x magnification would be necessary to fully assess the depth of the chatoyancy and ensure surface irregularities are not stabilized with resins. For higher valuation, provenance confirming a specific Namibian mine source would be beneficial.

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