... crystal,synthetic spinel and corundumC.Grad range:AAAAA,AAAA,AAA,AA,AD.more than 15years international trading experience E ... Gems Co. ,LtdCommodity Flat Back Oval Cabochon Black Onyx Loose Gemstone Materialblack onyxQualityAAAAA, AAAA, AAAShapeflat back oval cabochonColorblackMOQ 100PCS ... be produced. The quality grades are including AAAAA, AAAA, AAA, AA, A. Its unique style, excellent quality, and ...