7" Septarian Slab DS2236 bone Due to its relatively good

Due to its relatively good hardness compared to some other opals

The formation of dendritic opal involves the infiltration of mineral-rich water into rock cavities

and light blue

often found in regions with ancient seabeds

From the Chibuku Mine in Zimbabwe

7" Septarian Slab DS2236 bone Due to its relatively good7" Septarian Slab Approx. Dimensions: 7x6x0. 5 inches Approx. Weight: 711 grams Locality: Mexico Slab stand is included. Septarian, a distinctive sedimentary rock, forms through the combination of calcite, aragonite, and limestone with organic matter and minerals such as iron sulfide. It develops in concretions within sedimentary deposits, often found in regions with ancient seabeds, notably in Utah, USA, Madagascar, and Morocco. These concretions