Sunstone is metallic in appearance due to the reflective inclusions of red, orange or green crystals. It is composed of oligioclase feldspar and the reflections of light are caused by inclusions of hematite or goethite within the stone. The color variations and the shimmer (often called "schiller") are caused by tiny crystals of copper metal contained in varying amounts and sizes within the stones. The darker stones contain larger amounts of copper. The reflective inclusions or red, orange, or green platy crystals give Sunstone its metallic glitter. It is sometimes often refered to as "Aventurine Orthoclase" or "Heliolite".
Sunstone is believed to strengthen the life force, bring luck, instill optimism and increase strength and vitality. Sunstone, ruled by the Sun and a gemstone of Leo, is thought to bring luck and romance to the wearer. It is helpful to the liver and kidneys and aids digestion.