3.74 Cts Real Lustrous Royal Blue Sapphire Oval Cabochon Thailand 10mm x 8mm Gemstone. The item "Natural Untreated Loose Cabochon Oval Blue Sapphire 10mm x 8mm x 4.5mm 3.74ct" is in sale since Wednesday, May 30, 2018. This item is in the category "Jewellery & Watches\Loose Diamonds & Gemstones\Sapphire\Natural Sapphires". The seller is "old_chapel" and is located in Llanfechain. This item can be shipped worldwide.