Synthetic Material (Not A Rock Or Mineral)

Sandstone

Clastic Sedimentary Rock (composed mostly of SiO2)

Diorite (or Gabbro/Gneiss stream pebble)

Diorite

Sandstone (Banded)

Clastic Sedimentary Rock (primarily SiO2)

Schist (Greenschist / Mica Schist)

Foliated Metamorphic Rock (rich in chlorite, muscovite, and quartz)

Weathered vuggy quartz-rich rock (probable silicified limestone or quartz breccia)

Microcrystalline quartz (SiO₂) with calcite (CaCO₃), iron oxides, and minor clay minerals

Bituminous Coal (with Anthracite or Vitrinite inclusion)

Organic-rich Sedimentary Rock (Carboniferous classification)

Shale or Siltstone

Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)

Rounded iron-rich pebble

Likely hematite/goethite-bearing quartzite or ironstone; exact identification requires testing

Weathered quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide staining

Basalt River Pebble

Basalt

Vesicular Basalt

Mafic Volcanic Rock (Basalt)

Sandstone Pebble

Arenite (SiO2 dominated)

Petrified Wood

Silicified Wood (Quartzo-feldspathic fossil wood)

Blue glass-like tumbled specimen

Most likely cobalt-blue slag glass or manufactured glass; not confidently identifiable as a natural mineral from the image

Laterite

Laterite (Ferricrete)

Porphyritic Rhyolite (Birdseye Rhyolite)

Rhyolite (Porphyritic texture)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (Ferruginous)

Arenite with Iron oxide staining (SiO2 with Fe2O3)

Quartzite

Quartzite

Quartz (likely Rose Quartz or Milky Quartz based on color)

Quartz (SiO2 - Silicon Dioxide)

Tumbled jasper or rhyolitic porphyry

Silicic volcanic rock, likely rhyolite (quartz- and feldspar-rich), possibly jasperized

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)

Sandstone

Arenite (primarily SiO2)

Sandstone

Arenite (SiO2 principal)

Gabbro

Gabbro

Quartz-bearing altered rock, possibly iron-stained quartz vein

Quartz (SiO₂) in a feldspathic/sericitized host, with iron-oxide staining

Diorite

Diorite (intermediate intrusive igneous rock)

Quartz-rich metamorphic fragment (likely mica schist)

Mica schist, probably muscovite–quartz schist

Quartz-rich rock fragment

Microcrystalline quartz (SiO₂), possibly chalcedony or quartz-bearing breccia

Porphyritic Basalt (or Andesite) containing Augite

Porphyritic Mafic Volcanic Rock

Polished green aventurine

Quartzite or quartz-rich rock containing fuchsite mica; mainly SiO₂

Likely weathered basalt or iron-rich volcanic rock

Basalt; primarily plagioclase feldspar, pyroxene, and possibly olivine with iron-oxide alteration

Shale

Fissile Mudstone

Greenstone

Metabasalt / Metavolcanic rock

Slate

Metamorphic Pelitic Rock

Slate

Foliated Metamorphic Rock

Granodiorite Pebble

Granodiorite (containing Quartz, Plagioclase Feldspar, and Biotite/Amphibole)

Lichen-covered graywacke or granitic glacial cobble

Indeterminate; likely quartz–feldspar–mica rock, possibly weathered granite or granodiorite

Sandstone (Water-worn)

Arenite

Goldstone (blue-goldstone–style glass) beads

Artificial aventurine glass, typically silica glass with copper inclusions; not a natural mineral

Weathered iron-rich rock, possibly meteorite

Uncertain; likely goethite/hematite-rich material, with meteorite possibility

Diorite

Intermediate Phaneritic Igneous Rock