Crystal Geode, Amethyst, 10"-15", Purple Crystal

IntroductionGeode, also known as crystal ball, is a common geological formation in the United States, Brazil and Mexico. It is essentially composed of bubble crystals inside the rock. Generally, the interior contains quartz crystals and chalcedony deposits, and its exterior is limestone. or related rocks. Others that are completely filled with crystals are called nodules.Composition characteristicsThe variety of crystal sizes, shapes and shades of color makes each geode unique. Some are pure quartz crystals, others are deep purple amethysts. Others may be agate, chalcedony or jasper, etc. Only cutting or breaking a geode can determine if it is solid and what crystals it contains.Cause of formationGeologists do not yet have a widely accepted theory of geode formation, but believe that geodes can form in any buried cavity. These cavities can be air bubbles in igneous rock, cavities under tree roots, or even burrows dug by animals. Over time, the outer walls of the cavity hardened and dis