Clear Quartz
SiO2 (Silicon Dioxide)
Category
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Clear Quartz
SiO2 (Silicon Dioxide)
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)
Shale (with minor calcite veining)
Clastic sedimentary rock (primarily clay minerals and quartz)
Red Jasper
Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz (Water-worn Pebble)
Silicon Dioxide (SiO2)
Sandstone
Clastic Sedimentary Rock (composed mostly of SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Carnelian and White Quartz Bracelet
Silicon Dioxide (SiO2) - specifically Carnelian (Chalcedony) and Rock Crystal/Snow Quartz
Water and Silt (Sedimentary Environment)
Suspended Sediment / H2O (dihydrogen monoxide)
Sandstone with Tafoni Weathering
Arenite (SiO2 based)
Red Sandstone
Clastic sedimentary rock (primarily Quartz and Feldspar with Iron Oxide cement)
Banded Gneiss (with Quartz Vein)
Gneiss (Metamorphic rock of varying mineralogy)
Sandstone
Arenite (Siliclastic sedimentary rock)
Sandstone
Arenite (primarily SiO2)
Lake Superior Agate
Banded Chalcedony (Silicon Dioxide / SiO2)
Granodiorite Pebble
Granodiorite (containing Quartz, Plagioclase Feldspar, and Biotite/Amphibole)
Sandstone
Sandstone (clastic sedimentary rock)
Dolomite
Dolomite (CaMg(CO3)2)
Granite
Phaneritic Felsic Igneous Rock (Granite)
Sandstone
Arenite (variable SiO2 composition)
Banded Agate
Silicon Dioxide (SiO2)
Citrine
Silicon Dioxide (SiO2)
Blue Lace Agate
Cryptocrystalline Quartz (SiO2) with trace minerals
Blue Agate (Tumbled and Dyed)
Silicon Dioxide (SiO2) with likely organic dyes
White Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (Raw Chunk)
Silicon Dioxide (SiO2)
Diamond
Carbon (C)
Sandstone
Arenite (composed primarily of SiO2)
Vesicular Basalt (Iron-rich)
Scoriaceous Basalt / Oxidized Vesicular Basalt
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite (SiO2 based with quartz, feldspar, or lithic fragments)
Granite (with alteration)
Granite (Felsic intrusive igneous rock)
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Sandstone (Red)
Arenite (primarily SiO2 with Iron Oxide staining)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with FeO(OH) impurities)
Turquoise
Hydrated copper and aluminum phosphate (CuAl6(PO4)4(OH)8·4H2O)
Milky Quartz
Silicon Dioxide (SiO2)
Sandstone
Arenite (composed primarily of SiO2)