Amber is a fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects.
agate is a common stone formation, consisting of chalcedony and quartz as its main components, consisting of a wide variety of colors. agates are primarily formed within volcanic and metamorphic stones.
alexandrite is the highly regarded color changing variety of chrysoberyl. the color of alexandrite changes under different lighting conditions. if viewed in daylight, its color is greenish blue to dark yellow-green.