Amethyst Geode with Excellent Colour
A beautiful amethyst geode from Uruguay.
A geode is a fascinating geological structure. It's a rock with a hollow cavity in which crystals have grown slowly over millions of years.
These stunning formations offer a glimpse into the Earth’s geological history.
Amethyst geodes, with their striking purple crystals, make beautiful display pieces.
Geodes begin as hollow cavities within rocks, often volcanic or sedimentary. Over time, water rich in dissolved minerals seeps into the cavity, and as the water dries up, crystals begin to grow.
This process takes place over millions of years.
The first crystals to grow are usually clear or milky quartz. These crystals are typically white because they’re composed of pure silica.
As they continue to grow, conditions within the geode change, and iron from the surrounding rock or groundwater seeps into the cavity.
The presence of iron, combined with natural radiation, turns the quartz crystals purple.
In an amethyst geode, the white crystals formed first and remained white because of insufficient iron.
Later crystals were purple because they formed from an iron-rich solution and were then exposed to heat through natural radiation.
The dark layer at the base of the geode is the original host rock in which the crystals grew.
This incredible geological process, unfolding over millions of years, slowly created the beautiful amethyst geodes we enjoy today.
Amazonite
