sedimentary
Septarian (Dragon Stone)
Septarian Nodule (Aragonite, Calcite, Limestone)
Hardness: 3.5-4; Color: Yellow/brown/grey; Luster: Waxy to vitreous; Structure: Trigonal/Orthorhombic; Specific Gravity: 2.7-2.9
- Hardness
- 3
- Color
- Yellow/brown/grey
- Luster
- Waxy to vitreous
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Physical properties
Hardness: 3.5-4; Color: Yellow/brown/grey; Luster: Waxy to vitreous; Structure: Trigonal/Orthorhombic; Specific Gravity: 2.7-2.9
Formation & geological history
Formed as nodules in seabed mud about 50-70 million years ago during the Cretaceous period. Shrinkage cracks were later filled with calcite and aragonite.
Uses & applications
Decorative pieces, jewelry, metaphysical collecting, and ornamental carvings.
Geological facts
The name comes from the Latin word 'septum', referring to the partitions or cracks that separate the minerals inside the nodule.
Field identification & locations
Look for distinctive 'crackled' patterns of yellow calcite and brown aragonite within a grey limestone matrix. Primarily found in Madagascar and Utah.
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