Igneous Or Metamorphic

Yellow Calcite

Calcium Carbonate (CaCO3)

Optical Calcite (Iceland Spar)

Calcite (Calcium Carbonate, CaCO3)

Yellow Quartz (Citrine Quartzite)

Silicon Dioxide (SiO2)

Lemon Quartz (Orizaba/Citrinated Quartz)

Silicon Dioxide (SiO2) with iron impurities/treatment

Optical Calcite

Calcium Carbonate (CaCO3)

Moonstone

Orthoclase (Potassium aluminum silicate - KAlSi3O8)

Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz Crystal (specifically Rock Crystal)

Silicon Dioxide (SiO2)

Black Tourmaline

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

Peach Moonstone

Potassium Aluminum Silicate (KAlSi3O8)

Milky Quartz

Silicon Dioxide (SiO2)

Unakite

Unakite Epidosite (Granite with epidote and orthoclase)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Smoky Quartz (Tumbled)

Smoky Quartz (Silicon Dioxide - SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Weathered quartz-rich pebble

Likely quartzite or felsic granitoid fragment; predominantly SiO₂ quartz with minor feldspar and dark iron-bearing minerals

Hematite

Iron(III) oxide (Fe2O3)

Green Aventurine

Quartz variety (SiO2 with inclusions of Fuchsite)

Amethyst (Tumbled Quartz)

Silicon Dioxide (SiO2)

Quartz crystal cluster

Quartz (silicon dioxide, SiO₂)

Amethyst

Silicon Dioxide with Iron Impurities (SiO2)

Citrine Quartz

Silicon Dioxide (SiO2)

Aura Quartz (Titanium/Rainbow Quartz)

SiO2 (Silicon Dioxide) with metallic coating

Smoky Quartz

Silicon Dioxide (SiO2)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Common Quartz Pebble

Silicon dioxide (SiO2) rock fragment

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz

Silicon Dioxide (SiO2)

Blue aventurine quartz (likely)

Quartz, silicon dioxide (SiO₂), probably blue aventurine variety

Weathered iron-rich rock, possibly goethite/limonite-bearing basalt or ironstone

Indeterminate; likely Fe-oxide/hydroxide-rich silicate rock, dominated by goethite (FeO(OH)) and/or hematite (Fe₂O₃)

Likely iron-stained quartz or feldspar fragment

Quartz (SiO₂) or potassium feldspar (KAlSi₃O₈), uncertain from image

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Smoky Quartz Cluster

Smoky Quartz (Silicon Dioxide - SiO2)

Milky Quartz with inclusions

Silicon Dioxide (SiO2)

Tumbled dark blue-green stone, likely blue apatite or indigo gabbro

Apatite, Ca5(PO4)3(F,Cl,OH), or possibly quartz-rich indigo gabbro

Quartz-rich rock fragment, possibly granite or quartzite

Primarily quartz (SiO₂), with possible feldspar and iron-oxide staining

Epidote

{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

Gossan (Iron Hat)

Limonitic Gossan (Fe-oxide/hydroxide complex)

Small rounded mineral pebble, possibly feldspar or quartz

Uncertain from image; likely a quartz- or feldspar-rich grain

Milky quartz cluster

Quartz (silicon dioxide, SiO₂)

Smoky Quartz

Silicon Dioxide (SiO2)