This Is Not A Rock Or Mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Greenstone pebble (likely serpentinite)

Serpentinite, composed mainly of serpentine-group minerals

Weathered dark mineral/rock fragment

Indeterminate; possibly iron-rich basalt, slag, or a sulfide-bearing mineral

Feldspar (Plagioclase / Orthoclase)

KAlSi3O8 / CaAl2Si2O8 - NaAlSi3O8

Sandstone

Sandstone (composed primarily of sand-sized minerals or rock grains)

Quartz Geode

Silicon Dioxide (SiO2)

Muscovite Mica

Muscovite: KAl2(AlSi3O10)(OH)2

Veined basalt (likely basalt with quartz/calcite vein)

Basalt, aphanitic mafic volcanic rock; vein minerals likely quartz (SiO₂) or calcite (CaCO₃)

Peridotite (with Olivine and Pyroxene)

Ultramafic Magmatic Rock (Primary minerals: (Mg, Fe)2SiO4 and (Ca, Mg, Fe)2Si2O6)

Quartz Geode

Silicon Dioxide (SiO2)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

K-Feldspar / Granite Pegmatite

Potassium Feldspar (Microcline/Orthoclase) with Quartz

Man-made Ceramic / Clay Figurine

Aluminosilicate Ceramic (Processed Clay)

Smoky Quartz

Smoky Quartz (SiO2: Silicon Dioxide)

Likely quartz-rich stone or pale feldspar fragment

Indeterminate; possibly quartz (SiO₂) or feldspar (KAlSi₃O₈–NaAlSi₃O₈)

Dendritic Agate

Silicon Dioxide (SiO2) with Manganese/Iron inclusions

Natural gemstone and mineral collection

Mixed specimens, including turquoise, tiger’s eye, amethyst, fluorite, pyrite, garnet, rose quartz, lapis lazuli, obsidian, rhodonite, red corundum, labradorite, calcite, lepidolite, sodalite, apatite, and others

Quartz Geode

Silicon Dioxide (SiO2) in Host Rock

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Carved orange coral (likely bamboo coral)

Calcareous coral, principally aragonite (CaCO₃); possibly dyed bamboo coral, Isididae

Pink Granite / K-Feldspar

Alkali feldspar granite / Potassium feldspar (Microcline/Orthoclase)

Quartz (Rock Crystal) with minor impurities

Quartz (SiO2)

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Green glass sphere/marble

Soda-lime glass (primarily SiO2, Na2O, CaO)

Tumbled pale-green stone, possibly serpentine

Indeterminate; appearance is consistent with serpentine-rich rock (serpentine minerals, approximately Mg₃Si₂O₅(OH)₄)

Granite (Alkali-feldspar Granite)

Felsic Plutonic Rock (Primary minerals: Quartz SiO2, Orthoclase KAlSi3O8, Plagioclase (Na,Ca)AlSi3O8)

Biotite mica

Biotite, a potassium–iron–magnesium phyllosilicate mica; approximate formula K(Mg,Fe)₃AlSi₃O₁₀(F,OH)₂

Biotite Mica

Biotite (K(Mg,Fe)3(AlSi3O10)(F,OH)2)

Garnet Schist

Almandine Garnet in Mica Schist (Fe3Al2(SiO4)3)

Weathered geode or vug-bearing rock

Likely a quartz- or calcite-lined geode/vug in a host rock; exact minerals cannot be confirmed from the image

Sandstone with Iron Oxide (Limonite/Hematite)

Ferruginous Sandstone (SiO2 with FeO(OH)·nH2O)

Biotite Mica

Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)

Iron-stained rock fragment, possibly quartz-rich

Unidentified quartz-rich rock with iron-oxide staining (likely hematite/goethite)

Weathered iron-rich rock fragment

Likely limonite/goethite-bearing material; exact identification requires testing

Tumbled or naturally weathered quartz-rich stone, possibly iron-stained quartz

Quartz (SiO₂), with yellow-brown iron-oxide staining; exact identification is uncertain from the photograph

Brecciated marble (decorative stone slab)

Calcite-rich marble breccia; chiefly calcite (CaCO₃), potentially with dolomite and minor iron oxides

Epidote

Epidote (formula: Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Tumbled quartz-bearing rock, possibly garnet-bearing quartzite

Quartz-dominant silicate rock; visible minerals may include quartz, iron oxides, and dark mica or amphibole

Quartz-rich pegmatitic rock with possible epidote or chlorite

Hydrothermal/pegmatitic quartz-bearing rock; identifiable minerals may include quartz (SiO₂), feldspar, and epidote/chlorite

Breccia

Breccia - Clastic sedimentary rock

Biotite Mica in Host Rock

Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)