Description | The bladed mineral is kornerupine, Mg(Mg,Fe,Al)9(Si,Al,B)5O21(O,OH,F). It is in a sea of quartz that also contains small equant dark red garnets. Kornerupine is a rare mineral, sometimes prized as a gemstone (when it has an emerald green color). This sample from Woldheim, Germany, is about 5 cm across. |