Description :

Polished septarian nodule displaying classic angular calcite-filled cracks in dark gray to black limestone matrix. The specimen shows golden-yellow calcite crystal druzy filling the radiating septarian fractures, creating a dramatic star-burst pattern. Dark gray mudstone or limestone exterior with characteristic polygonal cracking pattern. The calcite-filled veins reveal sparkling crystalline surfaces where the nodule naturally fractured and mineralized. Brown oxidation zones visible along some crack boundaries between the calcite and host rock. The specimen has been cut into a circular disc and polished on both faces to showcase the internal septarian structure. Natural edge shows the original nodule exterior with fine crack patterns in the dark stone. Classic example of a concretion that dried and cracked, with the voids later filled by mineral-rich groundwater depositing calcite crystals. Likely Cretaceous to Jurassic age based on typical septarian formation periods.​​​​​​​​​​​​​​​​

Top Specimen: Septarian Slice

Measures- 5" x 4.5" 

• Flat cut showing blue-gray chalcedony banding and translucent crystalline layers.

• Likely a cross-section of a septarian nodule, revealing internal agate or chalcedony veins.

• The polished face highlights the concretion structure typical of septarian formations.

 Bottom Specimen: Septarian Half Nodule

Measures-3.5" W x 2" Tall 

• Rounded, natural exterior with a starburst of yellow calcite crystals radiating from the center.

• Surrounded by a brown-gray matrix — classic mudstone host.

• This is a textbook half-nodule, split to expose the dramatic internal crystal pattern.

  Disclaimer: 

  All gemstone and mineral descriptions are provided to the best of our ability based on visual assessment and available information. None of the stones in this auction have been GIA‑certified or professionally graded. The winning bidder is welcome to have any stone independently certified, graded, or appraised at their own expense. All items are sold as‑is.