Amethyst Geode Section - Large Chunky Piece
A magnificent section of an amethyst geode, with rich purple coloured crystals.
The
base of an amethyst geode is often white because the crystals grow from natural quartz, which is colourless or milky white. The purple colour develops over long periods of time.
Amethyst forms when silica-rich groundwater deposits quartz inside a rock cavity. Trace amounts of iron in the water become part of the crystal as it grows. Over time, natural radiation alters the iron, producing the purple colour. The base layer is often less affected, so remains white, or the colour is far less intense.
For amethyst to retain its rich purple colour, it should be positioned away from UV light.
This amethyst geode originates from Uruguay.
