sedimentary
Peanut Wood
Silicified (Petrified) Wood - SiO2 (Silicon Dioxide)
Hardness: 6.5-7 (Mohs scale), Color: Cream, tan, or white markings on a dark brown to black background, Luster: Vitreous to waxy (when polished), Crystal Structure: Microcrystalline (Cryptocrystalline), Cleavage: None
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Cream, tan, or white markings on a dark brown to black background, Luster: Vitreous to waxy (when polished), Crystal Structure: Microcrystalline (Cryptocrystalline), Cleavage: None
Formation & geological history
Formed through the petrification of driftwood in a marine environment. Specifically, the wood (Araucarian conifer) was riddled with boreholes from 'shipworms' (Teredo) before sinking and becoming agatized/silicified during the Cretaceous period (approx. 70-120 million years ago).
Uses & applications
Primarily used as a gemstone for jewelry (cabochons, pendants), ornamental carvings, and as a collectible geological specimen.
Geological facts
Peanut Wood is unique because it is wood that petrified in the ocean rather than on land. The 'peanuts' are actually white radiolarian silt that filled in the wormholes of the driftwood before it fossilized.
Field identification & locations
Found almost exclusively in the Kennedy Ranges of Western Australia near Carnarvon. Field identification relies on the distinct pattern of light-colored, oval 'worm-bore' marks against a dark carbonaceous wood background.
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