Septarian Nodules Polished Stones
Two distinctive septarian stones, carefully chosen for our collection.
Septarian is not particularly easy to polish because the yellow calcite crystals are very soft.
Septarian, which is a rock, not a mineral, is a nodule of hardened mud whose cracks were later filled with the minerals yellow calcite and either brown aragonite or siderite.
The name comes from the Latin septum, meaning a partition, after the network of filled cracks that divides each nodule.
Septarian from Madagascar comes from the Mahajanga basin in the northwest of the island, from rocks dated to the end of the Jurassic period.
