Lot 890* - A207 Out of This World - Monday, 04. December 2023, 04.00 PM
TWO SEPTARIAN NODULES
Oligocene, 50–70 million years
Belgium
39 × 36 × 5 cm (not including stand)
Belgium
39 × 36 × 5 cm (not including stand)
Septarian nodules are fossilised mud bubbles or round concretions found in sedimentary rocks, formed between 50 and 70 million years ago. Septarian is classed as a rock, not as a mineral. They are limestone concretions, hard solid masses formed by the accumulation of matter with sediment. There are several theories of how these nodules are formed, but since scientists have not yet agreed on the specifics, their formation remains a mystery. One theory suggests that they formed as a result of dehydration and shrinkage of clay, gel or organic cores within sedimentary pockets. Others believe there was an expansion of gases produced by the decay of organic matter that fractured material within such pockets.
Another theory suggests that an earthquake compaction or other geologic forces fractured material within sedimentary cavities. Whatever the cause, the sedimentary material fractured, and mineral-rich fluids filled the spaces between the breaks, allowing calcite, siderite, pyrite and other minerals to crystallize in the open areas within the cavity. It is almost like the Japanese Kintsugi repair method for ceramics, in which pulverised gold powder is inserted into the cracks of a broken object to make it relive anew in a mesmerising fashion.
These fabulous specimens are two almost identical septarian nodules, two concretions of rock, formed into egg–shaped natural sculptures and mounted on elegant, plain metal stands. The fine nodules are laced with chocolate calcite, and this combination of minerals makes for an interesting contrast in texture as well as colour.
These objects would be a very special addition to a collection of geological curiosities for any modern treasure hunter.
Another theory suggests that an earthquake compaction or other geologic forces fractured material within sedimentary cavities. Whatever the cause, the sedimentary material fractured, and mineral-rich fluids filled the spaces between the breaks, allowing calcite, siderite, pyrite and other minerals to crystallize in the open areas within the cavity. It is almost like the Japanese Kintsugi repair method for ceramics, in which pulverised gold powder is inserted into the cracks of a broken object to make it relive anew in a mesmerising fashion.
These fabulous specimens are two almost identical septarian nodules, two concretions of rock, formed into egg–shaped natural sculptures and mounted on elegant, plain metal stands. The fine nodules are laced with chocolate calcite, and this combination of minerals makes for an interesting contrast in texture as well as colour.
These objects would be a very special addition to a collection of geological curiosities for any modern treasure hunter.
To see this Object in a Video, click here
CHF 2 500 / 3 500 | (€ 2 580 / 3 610)
Sold for CHF 3 750 (including buyer’s premium)
All information is subject to change.