This is a very nice Amethyst “portal” geode from Brazil. This was formed from air getting trapped to form an air bubble as a cave was flooded for about 5 million years. Then when, the cave naturally drained over a few more million years, the shape of these geodes had formed within that air bubble. In this case the open was naturally formed - forming the “portal”. This one has no concrete as a backing to the exterior, just the natural green basalt mineral - which are harder to find.
This is a very nice Amethyst “portal” geode from Brazil. This was formed from air getting trapped to form an air bubble as a cave was flooded for about 5 million years. Then when, the cave naturally drained over a few more million years, the shape of these geodes had formed within that air bubble. In this case the open was naturally formed - forming the “portal”. This one has no concrete as a backing to the exterior, just the natural green basalt mineral - which are harder to find.
Length 4”, Width. 7”, Height 16”
Weight. 19.3 lb
