Polished amber-like gemstone bead
Possibly amber (fossilized tree resin; composition varies)
Category
Browse biogenic material specimens identified by the Rock Identifier community.
Polished amber-like gemstone bead
Possibly amber (fossilized tree resin; composition varies)
Mudstone
Lutylite (group of fine-grained sedimentary rocks)
Iron-rich jasper or hematite-bearing chert
Microcrystalline quartz (SiO₂) with hematite/goethite (Fe₂O₃/FeO(OH))
Blue sodalite-bearing rock, possibly lapis lazuli
Sodalite (Na₈Al₆Si₆O₂₄Cl₂), commonly in lazurite–calcite–pyrite assemblages
Greenstone / altered mafic rock
Likely serpentinite or chlorite-rich metabasalt; exact identification requires testing
Unidentified purple mineral fragment
Possibly amethyst (quartz), but the image is insufficient for confident identification
Mica-rich schist (likely muscovite schist)
Muscovite–quartz schist; chiefly muscovite mica, quartz, and minor feldspar/biotite
Polished/tumbled yellow-brown chert (likely jasper)
Microcrystalline quartz (chalcedony), SiO₂, iron-oxide colored
Vesicular volcanic rock, likely scoria
Scoria; vesicular basaltic to andesitic volcanic rock
Fluorescent glassy mineral specimen, possibly hyalite opal
Hyalite (hydrated amorphous silica, SiO₂·nH₂O), tentative
Tumbled amazonite
Amazonite, green microcline feldspar (KAlSi₃O₈)
Quartz-rich iron-stained metamorphic rock (likely quartzite)
Quartzite; predominantly quartz (SiO₂) with iron oxides/hydroxides, possibly feldspar and mica
Likely tumbled iron-stained quartz or chalcedony
Quartz/chalcedony (SiO₂), possibly limonite-coated
Tumbled quartz-rich stone (likely milky quartz/quartzite)
Quartz (SiO₂), possibly quartzite with minor iron-oxide staining
Diorite
Diorite (intermediate intrusive igneous rock)
Sandstone
Arenite (SiO2 based with mineral cement)
Chert (Quartz var.)
Silicon Dioxide (SiO2)
Milky quartz pebble
Quartz (silicon dioxide, SiO₂)
Sandstone
Arenite (Sedimentary rock comprising sand-sized grains)
Cullet Glass / Slag Glass
Amorphous silica glass
Weathered greenish metamorphic rock, possibly serpentinite
Serpentinite, dominated by serpentine-group minerals (antigorite, lizardite, or chrysotile)
Likely weathered quartz-rich rock fragment
Uncertain; possibly quartz sandstone or a pale feldspathic rock
Amber
Succiniferous organic material (Succinite)
Chert / Flint
Microcrystalline quartz (SiO2)
Chert (Flint)
Microcrystalline quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Red jasper in a gray host rock (likely jasperized volcanic rock)
Microcrystalline quartz (SiO₂), iron-oxide–colored jasper, in a fine-grained volcanic or sedimentary matrix
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Banded iron formation fragment (likely hematite–magnetite ironstone)
Banded iron formation; chiefly hematite (Fe₂O₃), magnetite (Fe₃O₄), and microcrystalline quartz (SiO₂)
Dyed tumbled quartz (likely quartzite or quartz crystal)
Quartz, silicon dioxide (SiO₂)
Basalt with pale mineral veins/coating
Likely vesicular or altered basalt, with calcite or zeolite minerals
Polished brecciated jasper (likely Picasso jasper)
Brecciated microcrystalline quartz/chalcedony; mainly SiO₂ with iron- and manganese-rich matrix
Likely weathered iron-rich quartz or chert
Microcrystalline quartz (SiO₂), possibly limonite/goethite stained
Polished dragon blood jasper
Jasper, a microcrystalline variety of quartz (SiO₂), colored by iron oxides and other inclusions
Likely calcite-rich limestone
Calcite (CaCO₃), probably micritic or fossiliferous limestone
Petrified Wood / Fossilized Wood
Silicified Wood (Silicon Dioxide - SiO2)
Likely quartz-rich river pebble
Milky quartz or quartz-bearing granitic/gneissic fragment (SiO₂-dominant)
Jasper (likely red/brown jasper)
Microcrystalline quartz/chalcedony, SiO₂, colored mainly by iron oxides
Likely tumbled jasper or iron-stained quartzite
Microcrystalline quartz (SiO₂), possibly quartzite with iron-oxide inclusions
Greenish quartz-bearing rock, possibly serpentine or aventurine
Tentatively quartz (SiO₂) with green inclusions; exact identification requires testing
Concrete Fragment
Artificial Conglomerate (Cement and Aggregate)
Black onyx-style gemstone ring
Likely chalcedony (microcrystalline quartz, SiO₂), possibly dyed black; identification from the photo is uncertain