GIA Certified with Rarity Notable (Characteristics) Report Rare, Natural Blue-Green Grandidierite. Perfectly Suited as an investment & Collector's Gem Gem Details: GIA Certificate No. 1503397972 Species - Grandidierite Weight - 3.94 Carats Color - Blue-Green Shape - Cushion Cutting Style: Crown - Brilliant Cut Cutting Style: Pavilion - Modified Brilliant Cut Transparency- Transparent with beautiful Luster Measurements - 10.43 x 7.64 x 6.26mm Comments- None About Rarity and Origin you may check in GIA Notable Report Grandidierite is an extremely rare greenish blue orthorhombic borosilicate with the formula (Mg,Fe)Al3(BO3)(SiO4)O2. It is the magnesium end member in a solid-solution series where the stoichiometric concentrations of Mg and Fe will vary and determine the ultimate nomenclature of the mineral. Ominelite is the iron end member. The structure of grandidierite is made up of BO3 triangles; SiO4 tetrahedra; distorted AlO5, MgO5, and FeO5 trigonal bipyramids; and AlO6 octahedra. Grandidierite characteristically forms in translu Shipping will be via Fedex and DHL with ful insurance. Customs and Import fees are sole responsibility of the buyer.