Desert Varnish on Sandstone
Ferromanganese coating on Quartz Arenite
sedimentary
Category
Synthetic Polymer (Polylactic Acid)
Browse synthetic polymer (polylactic acid) specimens identified by the Rock Identifier community.
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Quartzite
Quartzite (SiO2)
metamorphic
Quartz Druzy (on Calcedony/Quartz base)
Silicon Dioxide (SiO2)
mineral
Dyed Dragon Vein Agate
Silicon Dioxide (SiO2) with artificial pigment
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Conglomerate
Clastic sedimentary rock (Polymictic Conglomerate)
sedimentary
Pumice
Pumice (Amorphous volcanic glass)
Igneous
Chert (Jasper variety)
Microcrystalline quartz (SiO2)
sedimentary
Ruby Zoisite
Anyolite (Ca2Al3(SiO4)3(OH) + Al2O3:Cr)
metamorphic
Yellow Chert (Chert / Jasper)
Silicon Dioxide (SiO2 / Microcrystalline Quartz)
sedimentary
Granite (Weathered)
Grano-diorite / Granite (SiO2 rich intrusive rock)
igneous
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
mineral
Rose Quartz
Rose Quartz (SiO2)
Mineral
Pink Feldspar
Orthoclase Feldspar (KAlSi3O8)
mineral
Granite
Intrusive igneous rock (SiO2 range 65-75%)
igneous
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Vesicular Basalt (or Scoria)
Vesicular Basalt (Aphanitic-vesicular volcanic rock)
igneous
Quartz Vein Rock
Quartz (Silicon Dioxide, SiO2)
igneous
Moonstone
Adularia (orthoclase) or Albite (plagioclase), a feldspar mineral (KAlSi3O8 or NaAlSi3O8 respectively, often a mixture)
mineral
Iron Meteorite
Siderite (Iron-Nickel Alloy)
mineral
Yellow Quartz (Citrine or Iron-Stained Quartz)
Silicon Dioxide (SiO2)
mineral
Concretionary Sandstone
Clastic Sedimentary Rock (Sandstone with secondary mineral cementation)
sedimentary
Amazonite
Amazonite (Microcline) - K(AlSi3O8)
mineral
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)
metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
metamorphic
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate Hydroxide - NaFe2+3Al6Si6O18(BO3)3(OH)3OH
mineral
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz (Agate/Chalcedony)
Silicon Dioxide (SiO2)
mineral
Dragon Vein Agate (Dyed/Treated)
Agate (SiO2)
mineral
Greywacke
Lithic Sandstone (Greywacke - (SiO2+Al2O3+Fe2O3))
sedimentary
Scoria (Vesicular Basalt)
Scoria (Extrusive Igneous Rock)
igneous
Quartz Cobble (River Rock)
Silicon Dioxide (SiO2)
mineral
Granite
Granite (composed mainly of Quartz, Feldspar, and Mica)
igneous
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron inclusions)
metamorphic
Red Jasper
Silicon Dioxide (SiO2)
sedimentary
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Granite
Granitoid
igneous
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and clay impurities
sedimentary