Quartzite Cobble
Quartzite (primarily SiO2)
metamorphic
Category
Mineral (Specifically A Mineraloid)
Browse mineral (specifically a mineraloid) specimens identified by the Rock Identifier community.
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Red Jasper
Jasper (a variety of Chalcedony, SiO₂)
Mineraloid (cryptocrystalline quartz)
Flint
SiO2 (Cryptocrystalline Quartz)
sedimentary
Chert (or Flint)
SiO2 (predominantly microcrystalline quartz)
Sedimentary
Chert / Flint
Cryptocrystalline quartz (SiO2)
sedimentary
Green Slag
Anthropogenic Silicate Glass
Mineraloid (Industrial byproduct)
Slag (Industrial Glass/Metal Waste)
Artificial silicate/ferro-silicate byproduct
Mineraloid (Industrial byproduct)
Pink Granite (Crystalline Granite)
Igneous Intrusive Rock (Felsic Plutonic)
igneous
Yellow Jasper
Silicon Dioxide with Iron inclusions (SiO2)
sedimentary
Jasper Breccia
Brecciated Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
sedimentary
Mahogany Obsidian
Natural Volcanic Glass (SiO2 with iron and magnesium oxides)
igneous
Chert (specifically Pink/Tan Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Pink Chert or Jasperized Chert)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Basalt (Vesicular/Scoria)
Basalt (Extrusive Mafic Rock)
igneous
River Rocks and Pebbles
Mixed Silica-rich Sediments (SiO2 based)
sedimentary
Basalt
Basalt (Mafic Igneous Rock)
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)
Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)
mineraloid / industrial byproduct
Chert (specifically Tan/Gray Chert)
Microcrystalline quartz (SiO2)
sedimentary
Chert (specifically Gray/Blue-Gray Chert)
Chert (SiO2)
sedimentary
Puddingstone (specifically Michigan/Gowganda Puddingstone)
Conglomerate (Jasper Conglomerate)
sedimentary
Porphyry (specifically Porphyritic Basalt or Andesite)
Porphyritic extrusive igneous rock (Mg,Fe)2SiO4 (Olivine inclusions/Plagioclase Feldspar)
igneous
Chert (specifically Brown Chert or Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Puddingstone (specifically Michigan/Gowganda Puddingstone)
Quartzite Conglomerate (Gowganda Formation)
sedimentary
Basalt with Vesicular Texture
Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Basalt River Pebble
Aphanitic Mafic Basalt
igneous
Basalt
Basalt
igneous
Quartzite Pebbles
Metamorphosed sandstone (SiO2)
metamorphic
Sandstone (River Cobble)
Arenite
sedimentary
Riverstone (Water-worn Quartzite)
Quartzite (SiO2)
metamorphic
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt River Pebble
Basalt (Mafic Volcanic Rock)
igneous
Basalt
Aphanitic Mafic Igneous Rock
igneous
Rounded gray pebble
Indeterminate; likely a water-worn silicate or carbonate pebble
sedimentary
Chert (specifically Red Chert / Flint)
Silicon Dioxide (SiO2)
sedimentary
Orange cabochon gemstone, likely amber or amber-like resin
Natural amber: fossilized plant resin (organic mineraloid), commonly succinite; exact identification requires testing
gemstone
Synthetic Resin / Plastic Figurine
Synthetic Polymer (Copolymer of Polyethylene or Resin)
Mineraloid-like Synthetic Material
Chert (specifically brown Chert or Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (specifically White Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically White Chert or Novaculite)
Silicon Dioxide (SiO₂)
sedimentary
Chert (specifically Flint or Jasper-Chert)
Silicon Dioxide (SiO2)
sedimentary
Chert (specifically Black Chert or Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary