Believe yellow CALCITE gem Polished square 15x14mm cabochon
Freeform Cabs > Rectangles Squares Miscellaneous Cabochons Cabachons Cabs Gems Think yellow Calcite polished gemstones 18mm squares single solitaire for wire wrapping or use in a cabochon setting Miscellaneous Cabochons Cabachons Cabs Gems http://facetroughgemstones.com/gem-store/product_info.php/products_id/4026