mineral
Tumbled green jasper or serpentine
Jasper: microcrystalline quartz (SiO₂); possible serpentine: Mg₃Si₂O₅(OH)₄
AI-generated identification · may be incorrectSmall polished/tumbled, opaque green-and-black specimen with a waxy to dull luster. Jasper has Mohs hardness 6.5–7; serpentine is softer at 2.5–5.5, so visual identification alone is uncertain.
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Physical properties
Small polished/tumbled, opaque green-and-black specimen with a waxy to dull luster. Jasper has Mohs hardness 6.5–7; serpentine is softer at 2.5–5.5, so visual identification alone is uncertain.
Formation & geological history
Green jasper forms when silica-rich fluids cement or replace volcanic material; serpentine forms by hydration and alteration of ultramafic rocks. These processes range from Precambrian to modern geological settings.
Uses & applications
Used as an ornamental stone, cabochon, bead, carving material, and inexpensive collectible; it has little industrial value in this small form.
Geological facts
The mottled appearance may also represent epidote-, chlorite-, or chrysoprase-bearing material sold commercially as green jasper. A hardness test and mineralogical analysis are needed for a definitive name.
Field identification & locations
Common sources include India, Madagascar, Brazil, Australia, and the western United States. Check streak, hardness, translucency, and specific gravity; avoid confusing it with dyed quartz or glass.
