Scoria
Scoria
Category
Browse amorphous solid specimens identified by the Rock Identifier community.
Scoria
Scoria
Oolitic Limestone
Oolitic Limestone (Calcium Carbonate, CaCO3)
Tumbled green aventurine (probable)
Quartz, SiO₂, with fuchsite mica inclusions
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
Dyed Blue Agate Slice
Silicon Dioxide (SiO2) with artificial dye
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Blue Calcite
Calcite (Calcium Carbonate, CaCO3)
Polished agate/jasper nodule
Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide impurities
Opalite
Synthetic opalescent glass
Blue Howlite (Dyed)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
Banded Calcite
Calcium Carbonate (CaCO3)
Peacock Ore
Bornite (Cu5FeS4)
Bornite (Peacock Ore)
Bornite (Cu5FeS4)
River Pebble / Quartzite Rock
Metamorphic Quartzite (primarily SiO2)
Mica Schist
Mica Schist
Quartz Pebble
Silicon Dioxide (SiO2)
River Stone (Sedimentary Sandstone/Quartzite)
Arenite/Quartzite transition specimen
River Stone (River Pebble)
Rounded Sedimentary Rock (Lithic Clast)
Quartz Pebble
Silicon Dioxide (SiO2)
Chert/Jasper
Microcrystalline Quartz (SiO2)
Chert (Gravel)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Basalt River Stone
Basalt (Aphanitic Mafic Igneous Rock)
Quartz Cobble (with Iron Oxide Staining)
Microcrystalline to Macro crystalline Quartz (SiO2)
River Stone (River Rock)
Smooth Clastic Sedimentary Rock
Gravel or Pebble
Clastic Sedimentary Grain (typically composed of Quartz or Silicate minerals)
River Stone (Basalt Porphyry)
Porphyritic Basalt
Scoria
Scoria (vesicular volcanic rock)
Basalt Water-Worn Pebble
Aphanitic Mafic Igneous Rock
Glauconitic Sandstone
Glauconitic Sandstone (Greensand)
Granite Pebble
Granite (Felsic Intrusive Igneous Rock)
Pumice
Pumice (a vesicular volcanic glass)
Basalt Pebble
Extrusive Mafic Volcanic Rock
Quartzite
Quartzite
Basalt River Stone
Basalt (Aphanitic Mafic Igneous Rock)
Chert (and/or River Pebble)
Microcrystalline silica (SiO2)
Iridescent coated quartz (likely synthetic/display gemstone)
Quartz, silicon dioxide (SiO₂), likely faceted and surface-coated; exact material cannot be confirmed visually
Tumbled quartz-rich stone, possibly blue quartz or granite
Quartz (SiO₂), with probable feldspar and dark accessory minerals
Polished green-and-white stone, likely serpentine or nephrite jade
Serpentine-group minerals, commonly antigorite/lizardite; possible nephrite (interlocking actinolite–tremolite)
K2 stone (azurite–granite)
Biotite granite hosting blue azurite (Cu₃(CO₃)₂(OH)₂), often with malachite and quartz
Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
White quartz pebble
Quartz (silicon dioxide, SiO₂)
Polished hematite-rich ironstone
Hematite (Fe₂O₃), likely with magnetite and iron-rich jasper/goethite