Amethyst Geode on Pin StandViolet crystal on a pin standthe interior of a geode turned outward. An amethyst geode begins as a hollow in ancient lava flow. Over millions of years, silica rich groundwater deposits quartz crystal along the interior wallslayer by layer, point by point. The iron and natural irradiation present in the host rock color the quartz violet, deepening in zones where growth slowed. This specimen is mounted on a pin stand, presenting the druzy interior face