Probable serpentinite (serpentine-rich rock)
Serpentinite; chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with possible magnetite and olivine remnants
metamorphic
Category
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Tumbled quartz-rich agate/geode fragment
Microcrystalline quartz (SiO₂), likely chalcedony with crystalline quartz and possible iron-oxide inclusions
mineral
Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Granite
Granite (Phaneritic Quartz-Feldspar rock)
igneous
Jasper
Silicon dioxide (SiO2)
sedimentary
Red Sandstone
Arenite (Fe2O3 rich)
sedimentary
Chert (and Jasper blend)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Blue goldstone beads
Man-made aventurine glass (silica glass with metallic copper inclusions), not natural lapis lazuli
mineral
Rose Quartz
Rose Quartz (SiO2)
mineral
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
mineral
Tumbled blue-green stone, likely chrysocolla-bearing jasper
Chrysocolla-rich chalcedony/jasper; commonly a mixture of chrysocolla (hydrated copper silicate, variable formula) and quartz (SiO₂)
mineral
Rounded greenstone pebble
Likely serpentinite or chlorite-rich metamorphic rock; exact identification requires testing
metamorphic
Tumbled polymict breccia (probable quartz-rich breccia)
Clastic breccia composed mainly of quartz, feldspar, and iron-oxide-stained rock fragments
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3)
sedimentary
Fossil-bearing sedimentary rock, possibly fossil wood or bone
Indeterminate silicified/carbonate fossil in sandstone or mudstone
fossil
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert Arrowhead
Microcrystalline Quartz (SiO2)
sedimentary
Slate
Slate (Foliated Metamorphic Rock)
metamorphic
Chert (or Flint)
SiO2 (Microcrystalline Quartz)
sedimentary
Concrete
Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)
sedimentary (anthropogenic / man-made)
Basalt
Basalt
igneous
Basalt (Water-worn pebble)
Mafic Igneous Rock (primarily Plagioclase feldspar and Pyroxene)
igneous
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Porphyritic Basalt (Chinese Writing Stone)
Porphyritic Basalt or Porphyritic Andesite
igneous
Fossil Coral
Scleractinia (Anthos), primarily Calcium Carbonate (CaCO3)
sedimentary
Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Conglomerate (River Rock Aggregate)
Conglomerate (Lithic-clast conglomerate)
sedimentary
Iron-rich quartzite or limonite-bearing rock
Quartzite (SiO₂) with iron oxides/hydroxides, chiefly hematite and goethite
metamorphic
Sunstone
Oligoclase or Andesine (Plagioclase Feldspar) - (Ca, Na)((Al, Si)2Si2O8)
mineral
Orbicular granite (likely larvikite/rapakivi-type granite)
Granite; chiefly quartz, alkali feldspar, plagioclase, with dark biotite/amphibole and iron-oxide veining
igneous
Gabbro
Gabbro
igneous
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Septarian Nodule Segment (Turtle Stone)
Septarian Concretion (CaCO3 with Siderite or Calcite infill)
sedimentary
Banded chert or flint pebble
Microcrystalline quartz (SiO₂), likely chert with a pale weathered/altered zone
sedimentary
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
sedimentary
Sandstone (specifically Arkose or Quartz Arenite)
Arenite (primarily SiO2 with possible Feldspar)
sedimentary
River Rocks (Polished River Pebbles)
Stream-rounded clastic sediments
Mixed (Sedimentary, Igneous, and Metamorphic)