Light Green Chalcedony Ring / 925 Silver Ring / Chalcedony Jewelry / Adjustable Size Ring / Engagement Ring / Presentation Ring Chalcedony is a mineral, also known as stone marrow. Chalcedony is actually a kind of quartz, which is a cryptocrystal of SiO2 and a variant of quartz (cryptocrystalline). It is produced in the form of milky or stalactites, usually in the form of kidneys, stalactites, grapes, etc., with a waxy