Chalcedony, (pronounced kal-seh-duh-nee), is a translucent, often grayish or milky, variety of quartz. Chalcedony can come in many different colors, forms, and patterns. It is a broad term used to describe a cryptocrystalline form of silica and includes the gemstones agate and jasper. Chalcedony has a long history as a jewelry gemstone and is a popular gem today because it has such a range of exquisite colors.
Blue Chalcedony Grading Card
