Huge, 12.5" Septarian "Dragon Egg" Geode - Removable Section

This is a huge, 12-1/2" Septarian "Dragon Egg" geode collected in the Betsiboka Region of Madagascar. The hollow cavity is full of shimmering, black calcite crystals. It is a hollow septarian nodule, which has been polished into an egg shape, and the natural cracked pattern of the septarian gives it the appearance of a dragons egg. There is a removable section of the egg which allows for the interior crystal lined cavity to be viewed. This geode is heavy, coming in at 41 pounds in total.

A spectacular display piece which would look great in your home/office or make a great gift for the Game of Thrones enthusiast you know. Comes with a round acrylic display stand.

Septarian or septarian nodules are concretions containing angular cavities or cracks, called "septaria", filled with calcite and aragonite. A concretion is a hard, compact mass of rock that often forms around decaying organic matter. In the case of septarian nodules, the concretions formed around decaying sea life in a marine environment.

The exact mechanism for how the cracks form in the concretions is a mystery. One possible mechanism is the dehydration of the clay-rich core of a concretion, causing it to shrink and crack. The cracks could also be caused by gas expansion produced by the decaying organic matter within a concretion. Earthquakes have also been suggested as yet another mechanism.

The cracks in the concretions are then filled in with minerals such as calcite (yellow), aragonite (brown), and sometimes pyrite, causing very interesting patterns. They have often been described as looking like dragon's skin. They are frequently found as geodes with hollow, calcite crystal-filled cavities. More rarely, the fossils that originally started the formation of the concretion are still preserved in the septarian.
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DETAILS
SPECIES
Septarian with Black Calcite
LOCATION
Ambondromamy, Betsiboka Region, Madagascar
SIZE
12.5" tall, 9" wide, 41 lbs
CATEGORY
SUB CATEGORY
ITEM
#78536