Amethyst red secondary hues. ‘Rose de France’ is defined by its markedly light shade of the purple, reminiscent of a lavender/lilac shade. These pale colors, were once considered undesirable but have recently become popular due to intensive marketing. Green quartz is sometimes incorrectly called green amethyst, which is a misnomer and not an appropriate name for the material, the proper terminology being prasiolite. Other names for green quartz are vermarine or lime citrine. Of very variable intensity, the color of amethyst is often laid out in stripes parallel to the final faces of the crystal. One aspect in the art of
Amethyst lapidary involves correctly cutting the stone to place the color in a way that makes the tone of the finished gem homogeneous. Often, the fact that sometimes only a thin surface layer of violet color is present in the stone or that the color is not homogeneous makes for a difficult cutting. The color of amethyst has been demonstrated to result from substitution by irradiation of trivalent iron (Fe) for silicon in the structure, in the presence of trace elements of large ionic radius, and, to a certain extent, the amethyst color can naturally result from displacement of transition elements