Man Made Material, Not A Natural Rock Or Mineral Specimen

Granite

Intrusive Igneous Rock (Granitic)

Iron-stained garnet-bearing rock, possibly almandine garnet

Garnet-group silicate, likely almandine (Fe₃Al₂Si₃O₁₂), in a quartz–iron-oxide matrix

Limestone with Calcite

Sedimentary Calcium Carbonate (CaCO3)

Black tourmaline bead bracelet

Schorl tourmaline, NaFe3Al6(BO3)3Si6O18(OH)4

Sandstone (lithic/greywacke variant)

Clastic sedimentary rock (primarily SiO2 with rock fragments)

Polygenetic Conglomerate (or Breccia)

Clastic Sedimentary Rock

Fossiliferous Limestone

Bioclastic Limestone (Calcium Carbonate, CaCO3)

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

Polished orbicular jasper

Orbicular jasper; microcrystalline quartz (SiO₂) with hematite/goethite and other silicate inclusions

Shale

Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)

Greenstone with Epidote or Quartz veins

Metabasalt (Greenstone facies)

Diorite with Weathering Rind

Course-grained intermediate plutonic rock (Diorite)

Diamond (set in a gold ring)

Carbon (C) - Adamantine cubic carbon

Fossilized echinoid (sea urchin), likely a flint/chalk-associated test

Echinoid fossil; likely a regular echinoid such as Echinocidaris or related taxon, composed mainly of recrystallized calcite (CaCO₃)

Dark vesicular volcanic rock, likely basaltic scoria

Scoria (vesicular basalt; composition commonly plagioclase, pyroxene, and iron-rich glass)

Siltstone

Siltstone (Detrital Sedimentary Rock)

Granitic gneiss (weathered, rounded cobble)

Foliated granitoid; primarily quartz, feldspar, and mica (composition commonly approximates granite)

Sandstone

Arenite (SiO2 based typically)

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Pink Stained Rock (Likely Quartzite or Sandstone with Iron Oxide Staining)

Quartzite (metamorphic) or Sandstone (sedimentary); coloration likely due to hematite or other iron oxides.

Quartzite Pebble

Quartzite (SiO2)

Greywacke Siltstone Pebble / Concretionary River Pebble

Siltstone / Argillite (Fine-grained Sedimentary Rock)

Greywacke (River Pebble)

Greywacke sandstone with quartz veining

Diamond (Heart Cut)

Carbon (C)

Likely porphyritic igneous rock (possibly granite or rhyolite)

Quartz–feldspar–mica aggregate; exact identification requires a fresh surface and tests

Petrified Wood

Silicified Wood (SiO2)

Sandstone (with Feldspathic/Arkose qualities)

Arenite (primarily SiO2 with KAlSi3O8 components)

Blue Chalcedony (likely dyed Agate)

Silicon Dioxide (SiO₂)

Marble

Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.

Banded gneiss

Gneiss; chiefly quartz, feldspar, and mica

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and mica (possibly gneissic if foliation is confirmed)

Citrine Quartz

Silicon Dioxide (SiO2)

Rough Diamond

Diamond (pure Carbon, C)

Tiger's Eye (often misinterpreted as Gold Ore in this context)

Pseudomorph of Quartz after Crocidolite (SiO2)

Chert (or Chalcedony) Nodule

Microcrystalline Quartz (SiO2)

Green Calcite or Prasiolite (Green Quartz)

Calcium carbonate (CaCO3) or Silicon dioxide (SiO2)

Jasper

Microcrystalline Quartz (Chalcedony), SiO2

Quartz-rich pegmatite or quartz vein rock

Mostly quartz (SiO₂), with probable feldspar and iron-oxide staining

Weathered quartz-rich rock, possibly sandstone or quartzite

Indeterminate; likely quartz sandstone (SiO₂-rich), possibly weakly metamorphosed quartzite

Weathered sandstone or siltstone

Clastic sedimentary rock, chiefly quartz and feldspar grains cemented by clay, silica, or iron oxides

Polished brecciated jasper

Jasper, microcrystalline quartz (SiO₂), with iron-oxide and other mineral inclusions

Mixed river pebbles and quartz-rich specimens

Polymictic fluvial gravel; likely quartz, quartzite, chert, and weathered feldspathic rocks