Rock crystal icosahedron From a domus on the block east of the Baths Last phase of use of the house: between the end of the grd and the end of the 4 century A.D. The obiect was preserved together with a group of other precious elements (four necklace valves glass paste, three gems for ring settings, a bronze axis from around 211-150 B.C.) in a wooden casket, of which part of the bronze lock remains. These are valuables objects, even dating back to more ancient periods, accumulated and stored inside a rich house deposit. The crystal icosahedron is a particularly ran and valuable object. It is a regular polyhedron with 20 faces made up of 20 equilateral triangles. On each of the triangles it is engraved a symbol of the Greek numerical system (which made use of alphabet letters). fron umber 1 to number 20. The object is probablu linked t philosophical theories, associated with Neoplatonism, and to magical properties that are not easily decipherable.
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AI Estimated Value
Not an official valuation
$250,000 - $400,000
AI estimate as of August 16, 2025 · verify with a professional before acting
AI-Generated · Verify before acting
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This analysis also relies on unverified notes provided by the user, which may be incomplete or inaccurate and could affect the result.
This exquisite item is identified as a Rock Crystal Icosahedron, a particularly rare and valuable object dating from between the end of the 3rd and the end of the 4th century A.D. It is a regular polyhedron, precisely fashioned with 20 faces, each an equilateral triangle. The material is transparent rock crystal, allowing light to beautifully pass through and highlight its multifaceted structure. Each of the 20 triangular faces is meticulously engraved with a symbol from the Greek numerical system, corresponding to numbers 1 through 20. The object appears to be in excellent condition, with no visible chips, cracks, or significant wear. Its surfaces are smooth and well-preserved, indicating good care or stable environmental conditions throughout its existence. The craftsmanship is highly detailed and precise, reflecting advanced geometric and lapidary skills for its period. It was discovered as part of a hoard of valuable objects, including other ancient pieces, within a wooden casket that also contained a bronze lock remnants, suggesting it was part of a preserved and valued collection within a wealthy household ('domus') near the Baths. Its historical context links it to philosophical theories, possibly Neoplatonism, and potentially esoteric or magical properties that are not fully decipherable today. This piece is a testament to ancient mathematical understanding, artistic skill, and the cultural beliefs of the time.
AI Appraisal Report
Upon examining the provided image and detailed description of the Rock Crystal Icosahedron, I assess its condition as excellent. The transparency of the rock crystal, the meticulous engraving of Greek numerical symbols (1-20) on each of its 20 equilateral triangular faces, and the reported lack of chips, cracks, or significant wear affirm its remarkable preservation. The precise craftsmanship speaks to advanced ancient geometric and lapidary skills. The item's discovery within a preserved hoard in a 'domus' near the Baths, alongside other valuable ancient artifacts, strongly supports its authenticity and historical context, linking it to the late 3rd to late 4th century A.D. as per the provided information.
The market for ancient artifacts, particularly unique mathematical or philosophical objects, is highly specialized. Comparables are exceedingly rare due to its specific form, material, and engraved numerical system. Demand for such a piece would come from major museums, dedicated private collectors of ancient scientific instruments, or institutions with interests in classical studies and philosophy. Its rarity is unparalleled; I am unaware of another identical rock crystal icosahedron with engraved numerals from this period. Its historical context, potentially linking to Neoplatonism and esoteric beliefs, significantly enhances its appeal and value. Factors impacting value include its outstanding condition, confirmed ancient provenance, unique form, and the intriguing intellectual and cultural associations.
It is crucial to note the limitations of remote appraisal. While the provided details are compelling, full authentication would require in-person examination to verify the material's crystalline structure, tool marks consistent with the period, and the patination/wear on the engravings. Scientific testing, such as Raman spectroscopy for material identification and careful examination of inclusions, along with more extensive provenance documentation beyond the discovery context, would provide definitive authentication.
