Chrysoprase, chrysophrase or chrysoprasus is a gemstone variety of chalcedony (a cryptocrystalline form of silica) that contains small quantities of nickel. Its color is normally apple-green, but varies to deep green. The darker varieties of chrysoprase are also referred to as prase. Chrysoprase is apple-green chalcedony that derives its color from nickel. Its hardness and striking color make it a popular gemstone for jewelry as well as carvings. A variety of chalcedony, chrysoprase is a cryptocrystalline quartz gemstone. Transparency ranges from nearly opaque to nearly transparent. Its colors range from apple to olive green and nearly pure greens with medium tones.Chrysoprase opens, activates and energises the heart and sacral chakras, balances yin-yang energy, and brings Universal energy into the physical body. It induces deep meditative states, and imparts a sense of being a part of the divine whole. Chrysoprase is a strong detoxifying stone.