sedimentary
Green Jasper / Chert Pebbles
Microcrystalline Quartz (SiO2)
Hardness 6.5-7 on Mohs scale, waxy to dull luster, smooth water-worn surface with subtle fracturing, opaque greyish-green color, microcrystalline (cryptocrystalline) structure.
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Physical properties
Hardness 6.5-7 on Mohs scale, waxy to dull luster, smooth water-worn surface with subtle fracturing, opaque greyish-green color, microcrystalline (cryptocrystalline) structure.
Formation & geological history
Formed in marine sedimentary environments where silica-rich fluids precipitated microcrystalline quartz. Subsequently eroded and naturally rounded by wave action or river transport on coastal beaches.
Uses & applications
Commonly collected as river or beach pebbles, used in rock tumbling, landscape design, decorative aquariums, or lapidary arts.
Geological facts
Water-rounded beach stones like this often owe their grey-green color to trace inclusions of chlorite, epidote, or iron silicate minerals within the quartz matrix.
Field identification & locations
Can be identified in the field by its hardness (scratches glass), smooth water-rounded shape, and lack of visible crystalline grains. Very common along coastal beaches and gravel riverbeds worldwide.
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