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Septarian or septarian nodules are concretions containing angular cavities or cracks, called "septaria" which have become 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 …Typical "septarian nodule" from southwest Dallas, approx. 25 cm. across. These are often locally called "fossil turtles", when really they are fossil mud-balls with cracks that filled in with calcite. I have seen nodules the size of a small car in southwest Dallas. K. Nash specimen & image.Natural Utah Septarian Nodule 925 Sterling Silver Ring s.5.5 BR179208. $5.58. 3 bids. $5.95 shipping. 4h 55m. Septarian Nodule! Hollow Half. Unique mix of rock, mineral and organic matter! $35.00. A septarian nodule is a rounded gray limestone concretion with prominent cracking, filled with brownish orange aragonite and golden calcite crystals. They ...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. The host concretion is typically brown, gray, yellowish or reddish due to the mineral composition of the original mudstone. Contrasting vibrantly with the mute concretion colors are the bright white, yellow or clear infillings of the cracks. ... Cabochons cut from septarian nodule sections make ideal focal points for rings, pendants, bracelets ...Concretions and nodules, which may also be composed in part of the iron oxy-hydroxides such as limonite and goethite, come in a wide variety of shapes. Sometimes they are shiny on the surface, which might give the impression of a meteorite fusion crust. Note that while pure hematite is rich in iron, it does not attract a simple magnet. Liver nodules, usually a sign of liver disease, can be caused by certain parasitic or viral infections, immune system abnormalities, cancer and genetic conditions, according to Mayo Clinic.Sep 18, 2023 · As the mudstone erodes, the tougher concretion nodules are left behind. Septarian concretions form as nodules or irregular blobs ranging from a few inches to several feet across. They are composed primarily of calcite and aragonite, two carbonate-rich minerals that make up limestone . A concretion is a hard, compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word 'concretion' is derived from the Latin concretio " compacting, condensing, congealing, uniting", itself from con meaning 'together' and ... Septarian or septarian nodules are concretions containing angular cavities or cracks, called "septaria" which have become 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 …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. Septarian concretions are abundant in many Phanerozoic marine and marginal-marine shales and mudstones. They range from a few centimetres to several metres in size and are spherical or ellipsoidal in morphology. In general, formation by localized calcite or siderite cementation in argillaceous sediments began under less than a few metres of burial.Normally, a nodule has a warty or knobby surface and exists as a discrete mass within the host strata. In general, they lack any internal structure except for the preserved remnants of original bedding or fossils. Nodules are closely related to concretions and sometimes these terms are used interchangeably. Minerals that typically form nodules ...

Check out our septarian concretion selection for the very best in unique or custom, handmade pieces from our home & living shops.Septarian concretions (we prefer concretions to nodules, since the term concretion is generally used for regular and nodule for irregular diagenetic bodies: Pettijohn, 1975) are characterised by two sets of fractures, a concentric set and a radial set (Austin, 1986; Fig. 1). Fractures of the radial set are thickest near the This Rocks & Geodes item by CosmicCrysDals has 12 favorites from Etsy shoppers. Ships from Saratoga Springs, NY. Listed on Jul 13, 2023Septarian nodules are actually a concretion. They're also among the most interesting since the interior minerals have cracked through the exterior which forms a mottled coloration. This polishes up well and they can sometimes be seen cut as polished slabs or even cabochons. ... Septarian nodules are primarily found in carbonate-rich mudstones ...Normally, a nodule has a warty or knobby surface and exists as a discrete mass within the host strata. In general, they lack any internal structure except for the preserved remnants of original bedding or fossils. Nodules are closely related to concretions and sometimes these terms are used interchangeably. Minerals that typically form nodules ...

Septarian concretions or septarian nodules are sometimes called Dragon Eggs. They form primarily in an ocean setting just below the sediment surface through a series of steps. Some sort of nucleus, such as a fossil, is buried in the sediment. Fine grained calcite mud precipitates around this nucleus and a hard mud ball is formed. The longer the ocean level stays relatively constant, the bigger ... Septarian or septarian nodules are concretions containing angular cavities or cracks, called "septaria" which have become 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 ……

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs. Septarian or septarian nodules are concretions conta. Possible cause: This is a cut and polished septarian nodule from Morocco. Each half is about 3.35" .