Chrysoprase is a gemstone variety of Chalcedony that receives its green color from trace amounts of nickel and more rarely with the addition of chromium or chlorite. It is a cryptocrystalline made up of micro crystals that are too small to identify under normal magnification. Other closely related cryptocrystalline silicas include Agate, Carnelian and Chalcedony of other color shades. Chrysoprase lis made of very fine crystal ingrowths of quartz and moganite. It is a nearly pure Silicon dioxide with trace elements that cause its coloration. It can be semitransparent to translucent and has a hardness like that of quartz, 6.5 - 7 Mohs.

The name Chrysoprase is a combination of two ancient Greek words, ‘chrusos’ meaning golden and ‘prason’ meaning leek, the ‘golden leek’ describing the typical color of Chrysoprase.  Brightly colored Chrysoprase with a high translucency are considered to be the most valuable. The biggest sources for gem quality Chrysoprase include Tanzania, Poland, Indonesia, Brazil and Queensland, Australia who produce more than 80% of the world’s supply.