Metamorphic Or Igneous (Context Dependent)

Granite

Phaneritic Igneous Rock (composed of Quartz, Feldspar, and Mica/Amphibole)

Orange Calcite

Calcium Carbonate (CaCO3)

Yellow Aventurine

Quartz (Silicon Dioxide, SiO2) with inclusions

Dinosaur Skull Fossil (Velociraptor Replica)

Velociraptor mongoliensis fossil specimen in sedimentary matrix

Quartz Druzy / Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Weathered quartz-rich rock (likely quartzite)

Quartzite, composed predominantly of quartz (SiO₂); identification is tentative from the photo

Tumbled citrine or iron-stained quartz

Quartz (SiO₂), likely iron-oxide-stained or natural citrine

Green Aventurine

Quartz (SiO2) with Fuchsite inclusions

Basalt Metate

Vesicular Basalt

Granite

Granite (Felsic Plutonic Rock)

Ruby (Cabochon)

Corundum (Al2O3)

Weathered quartz-rich rock, possibly chert or quartzite

Likely microcrystalline quartz (SiO₂), but exact identification is uncertain from the photograph

Weathered quartz-rich rock, likely sandstone or quartzite

Quartz (SiO₂)-rich sandstone; possibly partially metamorphosed quartzite

Efflorescence (on Clay Brick)

Crystalline salt deposits (typically Sodium Sulfate Na2SO4, Calcium Carbonate CaCO3, or Potassium Sulfate K2SO4)

Quartzite

Quartzite (SiO2)

Basalt (with Brass Inlay)

Basalt (Mafic volcanic rock)

Chromium (Chrome)

Chromium (Cr)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Dark granitic gneiss or fine-grained granite

Biotite granite, possibly weakly foliated gneiss; quartz–feldspar–biotite assemblage

Olivine Diabase Porphyry

Porphyritic Olivine-Bearing Diabase (Micro-Gabbro)

Slag Glass

Silicon dioxide with impurities

Granite

Granite (Phaneritic igneous rock composed of Quartz, Feldspar, and Mica)

Fossil Snail

Gastropoda (fossilized)

Polished rose quartz

Quartz (silicon dioxide, SiO₂), rose-colored variety

Granodiorite

Granodiorite

Granite

Phaneritic Plutonic Felsic Rock

Porphyritic polymictic breccia (likely volcanic breccia)

Volcanic breccia; probable polymictic andesite–dacite breccia with quartz/feldspar clasts

Hematite (Tumbled)

Iron(III) oxide (Fe2O3)

Green quartz pebble, possibly aventurine

Quartz (SiO₂), likely fuchsite-bearing aventurine quartz

Rounded pink granite or granitic river pebble

Granite; mainly quartz (SiO₂), alkali feldspar, plagioclase, and minor mica/iron oxides

Peridotite (Olivine)

Peridotite (comprising (Mg,Fe)2SiO4)

Large granite boulder

Granite, a coarse-grained intrusive igneous rock composed mainly of quartz, feldspar, and mica

Angular gray rock fragments

Unidentified fine-grained rock; the image does not show diagnostic features sufficient for a specific identification

Red obsidian (likely mahogany obsidian)

Volcanic glass; primarily silica-rich rhyolitic glass (SiO₂), commonly with iron-oxide inclusions

Quartz-rich pegmatite, possibly with mica

Granite/pegmatite composed mainly of quartz (SiO₂), feldspar, and likely biotite or muscovite mica

Blue Sapphire (in a faceted jewelry setting)

Corundum (Al2O3) with trace Iron and Titanium

Granite

Granite (Phaneritic igneous rock)

Dark slate (probable)

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz; exact identification is uncertain from the photograph.

Blue Sapphire

Corundum (Al2O3)

Granite

Phaneritic Plutonic Felsic Rock

Granite

Phaneritic Plutonic Felsic Rock (K-Feldspar + Quartz + Plagioclase)

Blue-gray kyanite crystal

Kyanite (Al₂SiO₅)