Concretions are formed from mineral precipitation around some kind of nucleus while a nodule is a replacement body. Descriptions dating from the 18th century attest to the fact that concretions have long been regarded as geological curiosities.

Nov 8, 2022 · Septarian nodules are a type of concretion where mudstone of some kind is interspersed with calcite or another carbonate-rich mineral. The calcite portions follow the pattern of radiating cracks, which occur during the unique creation of these formations.

Some of the most curious objects in the natural world are the nodules, or concretions, that are found in clay strata that was originally mud laid down on the sea floor millions of years ago, and of these, septarian nodules are perhaps the most attractive and bizarre.

Nodule, rounded mineral concretion that is distinct from, and may be separated from, the formation in which it occurs. Nodules commonly are elongate with a knobby irregular surface; they usually are oriented parallel to the bedding.

In geology and particularly in sedimentology, a nodule is a small, irregularly rounded knot, mass, or lump of a mineral or mineral aggregate that typically has a contrasting composition from the enclosing sediment or sedimentary rock. Examples include pyrite nodules in coal, a chert nodule in limestone, or a phosphorite nodule in marine shale.

Jan 2, 2025 · While they certainly look unusual enough to question their origin, septarian nodules are naturally occurring geological formations. They form in sedimentary rock, usually when minerals precipitate within the mud or clay. Over time, the minerals harden and create these distinct nodules.

Nov 18, 2023 · Septarian, also known as Septarian Nodule or Dragon Stone, is a distinctive type of sedimentary rock that is characterized by its unique, striking appearance. It is composed primarily of a combination of minerals, including calcite, aragonite, and limestone, with additional components such as clay minerals, gypsum, and barite.

Mar 25, 2025 · This paper investigates the potential for experimental archaeology and X-radiography to improve our understanding of the manufacture and use of two categories of prehistoric Cretan administrative clay objects: clay tablets and hanging nodules.

Mar 28, 2023 · Septarian nodules, also known as dragon stones, are highly sought after by rock hounds and mineral collectors because they formed millions of years ago in a unique way. These dark mud balls are distinctive stones with yellow, gray, and brown tones in large art-like bands.

In a recent re-examination of the Garoga site collection, we realized that complementary study of both the pottery sherds and clay nodules could lead to new insights into ancient pottery manufacture at Garoga and its roles in the lives of the Kanien’keha:ka (Mohawk) inhabitants.