This sphere is carved from septarian, a unique rock formed from a combination of minerals including calcite, aragonite, and limestone. Septarian nodules develop when mineral-rich mud cracks and fills with calcite or aragonite over millions of years, creating striking patterns of yellow, brown, and gray.
Details:
- Material: Septarian (limestone with calcite and aragonite)
- Size: Approximately 2 to 2.5 inches in diameter
- Appearance: Polished sphere displaying contrasting yellow calcite, brown aragonite, and gray limestone in natural crack-like patterns
- Formation: Forms from ancient marine sediment that hardened, cracked, and later filled with mineral deposits
- Physical Properties: Mohs hardness 3–4.5 depending on mineral composition; smooth polished surface
- Educational Value: Demonstrates sedimentary rock processes, mineral infill in natural cracks, and the combination of multiple minerals in a single specimen
This septarian sphere combines geological history with striking natural patterns, making it both a decorative object and an engaging educational specimen.