Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Category
Organic (Often Found By Beachcombers)
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Amber
Succinite (specifically for Baltic amber); Chemical formula approximately C10H16O
mineral
Amber
Succinite (specifically for Baltic amber); Complex mixture of organic compounds (C10H16O)
Organic Mineraloid
Pyrite
Pyrite (FeS2)
Mineral
Chert / Flint
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Chert (varietal: Flint/Jasper mix)
Hydrous Silica (SiO2)
sedimentary
Chert / Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Mother of Pearl (Nacre)
Aragonite (layered with organic polymers), CaCO3
mineral
Ambergris
Ambra grisea (Metabolic byproduct)
Organic (Geological relative)
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chalcedony
Cryptocrystalline Quartz (SiO2)
mineral
Gray Chert (River Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Pearl and Garnet Glass
Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass
mineral and glass
Amber
Amber (Amorphous Organic Hydrocarbon)
mineral
Chert (Flint/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Amber
Succinite (Approximate formula: C10H16O)
Mineraloid
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Sedimentary Rock
Amber
Succinite (specifically for Baltic Amber), Formula: C10H16O
Mineraloid
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Man-made Object/Uncertain Mineral
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Amber
Succinite (specifically for Baltic amber); approximate formula C10H16O
organic mineraloid
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
mineral
Chert (River Pebble)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Anthracite Coal
Anthracite (Carbon-based metamorphic rock, 86-97% C)
metamorphic
Chert / River Pebble
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
sedimentary
Amber
Succinite (a common variety of fossilized resin)
mineral
Sandstone Pebble
Arenite (primarily SiO2)
sedimentary
Amber
Succinite (C10H16O)
mineraloid
Chert (specifically Gray Chert)
Chert (SiO2)
sedimentary
Fossiliferous Limestone with Rugose Coral
Calcium Carbonate (CaCO3) featuring Rugosa (extinct order of solitary and colony corals)
sedimentary
Petrified Wood
Silicified wood (primarily SiO2)
metamorphic
Moss Agate
Silicon Dioxide with inclusions (SiO2)
mineral
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
mineral
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
sedimentary