Limonite (Ironstone)
Limonite (mixture of hydrated iron(III) oxide-hydroxides)
Category
Browse industrial byproduct (anthropogenic material) specimens identified by the Rock Identifier community.
Limonite (Ironstone)
Limonite (mixture of hydrated iron(III) oxide-hydroxides)
Petrified Wood
Silicified Wood (SiO2)
Pink-and-white quartz-rich rock, likely rose quartz or quartzite
Quartz (SiO₂), possibly rose-quartz-bearing quartzite; minor iron-oxide staining
Riverstone (Siltstone/Mudstone)
Siltstone
Diamond
Native Carbon (C)
Petrified Rugose Coral (Horn Coral)
Order Rugosa (extinct coral)
Sedimentary Rock with Crafts (Pet Rock)
Sedimentary rock decorated with synthetic materials
Tumbled green aventurine (probable)
Quartz, SiO₂, with fuchsite mica inclusions
Flint
Microcrystalline quartz (SiO2)
Sandstone (with concrete/human-made layer)
Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)
Quartz Sand (Beach Sand)
Silicon Dioxide (SiO2)
Magnetite Sand (Black Sand)
Magnetite (Fe3O4)
Limestone
Sedimentary rock composed primarily of Calcite (CaCO3)
Quartzite
Quartzite (composed primarily of SiO2)
Quartzite
Quartzite (SiO2)
Pumice
Pumice (a highly vesicular volcanic rock)
Quartzite
Quartzite (SiO2)
Granodiorite
Granodiorite (intermediate plutonic rock)
Quartzite
Quartzite (SiO2)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
Bauxite
Bauxite (mainly Al(OH)3, AlO(OH))
Quartzite
Quartzite (primarily SiO2)
Pumice
Pumice (Alveolar Rhyolite / Dacite / Andesite)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Basalt
Basalt (Mafic volcanic rock)
Pink Granite
Granite (Alkali-feldspar granite)
Basalt
Basalt (Mafic volcanic rock)
Quartzite
Metamorphosed Quartz Arenite (SiO2)
Diabase (Dolerite) Cobble
Diabase / Dolerite
Tumbled green aventurine
Quartz variety, mainly SiO₂ with fuchsite or other mica inclusions
Chert (with Limestone/Dolomite host)
Microcrystalline Quartz (SiO2)
Scoria (Volcanic Rock)
Scoria (often basaltic scoria)
Coquina
Biogenic Limestone (Coquina)
Agate
Silicon Dioxide (Chalcedony), SiO2
Bumblebee Jasper
Calcite-bearing Volcanic Tuff containing Sulfur and Arsenic (Orpiment/Realgar)
Sandstone (Tumbled / Rounded)
Sedimentary Rock (Quartz arenite)
Flint
SiO2 (Cryptocrystalline Quartz)
Flint
SiO2 (Microcrystalline Quartz)
Flint (or Chert)
Microcrystalline quartz (SiO2)
Native Copper
Copper (Cu)
Jasper
Silicon dioxide (SiO2) with impurities, microcrystalline quartz
Jasper
Microcrystalline Quartz (SiO2)