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    Exceptional Gemstone: Color Change Blue Spinel - 14.33 Ct.
    Muhuwesi River, Tunduru District, Ruvuma Region, Tanzania

    The association between Sapphire (Al2O3) and Spinel (MgAl2O4) is sufficiently close that in many localities the two form together. To add to the confusion, both come in multiple colors and are only marginally different in hardness. As a result, it is not surprising to find that this cool blue gem, comes from a famous Sapphire locality: the Muhuwesi River in Tanzania. The same trace elements responsible for the gemstone's blue color are also responsible for a slight, but noticeable, color change between a violet-blue and a steely blue, depending on ambient lighting. It was found in 2003, probably in the dry season, when artisanal miners screen the gravels of the river when the annual flow is down. Later, it was faceted in an oval, mixed cut style in Bangkok, Thailand. The eye clean stone was examined by the AGL, resulting in a cert (#CS 65951) indicating that it has not been heated or otherwise enhanced.
    Measurements: 15.61 x 13.13 x 9.08 mm, 14.33 cts.
    Offered at no reserve.

    Provenance: Rainbow of Africa Collection
    Accompanied by AGL Certificate # CS 65951

    Condition Report*: Condition report available upon request.
    *Heritage Auctions strives to provide as much information as possible but encourages in-person inspection by bidders. Statements regarding the condition of objects are only for general guidance and should not be relied upon as complete statements of fact, and do not constitute a representation, warranty or assumption of liability by Heritage. Some condition issues may not be noted in the condition report but are apparent in the provided photos which are considered part of the condition report. Please note that we do not de-frame lots estimated at $1,000 or less and may not be able to provide additional details for lots valued under $500. Heritage does not guarantee the condition of frames and shall not be liable for any damage/scratches to frames, glass/acrylic coverings, original boxes, display accessories, or art that has slipped in frames. All lots are sold "AS IS" under the Terms & Conditions of Auction.

    Auction Info

    Auction Dates
    October, 2015
    15th Thursday
    Bids + Registered Phone Bidders: 4
    Lot Tracking Activity: N/A
    Page Views: 3,479

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