Organic Mineraloid

Browse organic mineraloid specimens identified by the Rock Identifier community.

Sugilite

Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)

Mineral

Pumice

Vesicular volcanic glass (primarily SiO2 with Al2O3)

Igneous

Fossilized Brachiopod

Phylum Brachiopoda (replaced by Calcite/CaCO3)

sedimentary

Fossiliferous Limestone

Limestone with fossil inclusions (CaCO3)

sedimentary

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Sedimentary rock

Pumice

Pumicite (Amorphous glass with varying chemical composition, often rhyolitic)

Igneous

Aragonite

Aragonite (CaCO3)

mineral

Fossilized Brachiopod

Brachiopoda (Class Rhynchonellata or Spiriferida)

sedimentary

Sandstone with trace fossil

Sandstone, possibly with Skolithos or similar trace fossil

sedimentary

Granite (likely a river or beach pebble)

Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)

Igneous

Fossil Sand Dollar (Echinoidea)

Phylum Echinodermata, Class Echinoidea (likely Dendraster or Scutella)

sedimentary

Jasper (Mookaite style)

Jasper (Silica-rich Microcrystalline Quartz, SiO2)

sedimentary

Pumice

Pumice (volcanic rock)

Igneous

Botryoidal Hematite (Kidney Ore)

Hematite (Fe2O3)

mineral

Magnetite

Magnetite (Fe3O4)

Mineral

Chert (Field Stone)

Microcrystalline Quartz (SiO2)

sedimentary

Fossiliferous Limestone

Limestone (composed primarily of calcite with included fossils CaCO3)

Sedimentary

Chert (Flint variety)

Silicon Dioxide (SiO2)

sedimentary

Chert (Flint)

Silicon Dioxide (SiO2)

sedimentary

Chert (Flint)

Microcrystalline Quartz (SiO2)

sedimentary

Hypersthene (or Enstatite/Ferrosilite)

Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)

Mineral