
57-Carat Untreated Purple Sapphire Pre-form
This item is a significant 57-carat natural purple sapphire specimen, currently in a rough pre-form state, which is a critical stage between a raw crystal and a finished gemstone. The specimen exhibits a rich, deep purple hue with notable red undertones, suggesting a high chromium or iron content characteristic of high-quality corundum. Measuring approximately the width of the accompanying US quarter (noted for scale), the stone shows a blocky, semi-rectangular silhouette. Its surface texture appears matte to slightly frosted from initial shaping, yet the depth of color saturation remains clearly visible. A key diagnostic feature is its reported strong fluorescence under ultraviolet light, which often indicates an absence of heat treatment. The interior clarity appears remarkably high for a specimen of this magnitude, free from large eye-visible fractures or heavy silk that would impede the faceting process. Expert assessment suggests this rough material is capable of yielding a finished faceted gemstone in the 20 to 30-carat range. The lack of artificial enhancements or thermal treatments places this in an elite tier of investment-grade mineral specimens, desirable for both high-end jewelry manufacturing and mineral collectors.
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Estimated Value
$57,000 - $85,000
Basic Information
Category
Loose Gemstones & Minerals
Appraised On
March 7, 2026
Estimated Value
$57,000 - $85,000
Additional Details Provided By Owner
User Provided Information
Natural 57-Carat Purple Sapphire – Loose, Untreated A rare, exceptional natural sapphire displaying deep purple with red undertones and bright natural fluorescence under UV light. With excellent clarity for its size and untreated, natural origin, this 57-carat pre-form has the potential to yield a 20–30 carat finished gemstone. Its size, color saturation, and collector-level quality make it a highly desirable specimen for investors and connoisseurs.
Item Description
This item is a significant 57-carat natural purple sapphire specimen, currently in a rough pre-form state, which is a critical stage between a raw crystal and a finished gemstone. The specimen exhibits a rich, deep purple hue with notable red undertones, suggesting a high chromium or iron content characteristic of high-quality corundum. Measuring approximately the width of the accompanying US quarter (noted for scale), the stone shows a blocky, semi-rectangular silhouette. Its surface texture appears matte to slightly frosted from initial shaping, yet the depth of color saturation remains clearly visible. A key diagnostic feature is its reported strong fluorescence under ultraviolet light, which often indicates an absence of heat treatment. The interior clarity appears remarkably high for a specimen of this magnitude, free from large eye-visible fractures or heavy silk that would impede the faceting process. Expert assessment suggests this rough material is capable of yielding a finished faceted gemstone in the 20 to 30-carat range. The lack of artificial enhancements or thermal treatments places this in an elite tier of investment-grade mineral specimens, desirable for both high-end jewelry manufacturing and mineral collectors.
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