Sedimentary (if natural Jasper) or Artificial (if Slag)
Jasper (Multi-colored) / Sea Glass Slag
Silicon Dioxide (SiO2) with impurities of Iron Oxide
Hardness of 6.5-7 on the Mohs scale. Opaque with a waxy to vitreous luster. This specific piece shows a conchoidal fracture and deep red and green coloration. Small white calcified circles are barnacle attachments.
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Physical properties
Hardness of 6.5-7 on the Mohs scale. Opaque with a waxy to vitreous luster. This specific piece shows a conchoidal fracture and deep red and green coloration. Small white calcified circles are barnacle attachments.
Formation & geological history
Formed through the accumulation of silica in volcanic ash or sedimentary deposits (naturally) or as a byproduct of glass manufacturing (artificially). This specimen has been submerged in a marine environment, evidenced by the barnacles and water-worn edges.
Uses & applications
Used primarily in lapidary work, jewelry making (cabochons), and as aquarium or decorative stones.
Geological facts
The presence of barnacles indicates this specimen spent significant time in intertidal zones or underwater. Jasper has been used since antiquity for seals and talismans, while 'sea glass slag' is highly sought after by beachcombers for its unique swirled patterns.
Field identification & locations
Identify by its extreme hardness (cannot be scratched by a steel knife) and smooth, shell-like fracture surface. Commonly found on coastlines near ancient volcanic or industrial areas. Collectors should look for unique 'brecciated' or multi-colored patterns.
More like this
Other sedimentary (if natural jasper) or artificial (if slag) specimens
Iron Slag
Anthropogenic Vitreous Silicate (Byproduct of Smelting)
Mineral-like byproduct
Slag (Industrial Glass)
Artificial Vitreous Silicate
mineraloid (anthropogenic)
Slag (Industrial Byproduct)
Ferrous/Non-ferrous Silicate
igneous (artificial/anthropogenic)
Red Dyed Howlite
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Dyed Quartz Geode
Silicon Dioxide (SiO2) with artificial pigment
mineral
Ferrochrome Slag
Anthropogenic silicate/oxide glass (Complex silicate matrix with Cr-Fe-Si inclusions)
Industrial byproduct (often confused with igneous rocks or meteorites)