Not A Rock Or Mineral

Granite (Pink/Red)

Phaneritic Plutonic Felsic Rock (major minerals: Quartz, Orthoclase Feldspar, Plagioclase Feldspar)

Banded gneiss pebble

Gneiss, a foliated metamorphic rock; exact mineral composition cannot be determined from the image

Quartz-veined altered rock

Likely quartz-bearing metasediment or altered igneous rock; vein mineral: quartz (SiO₂)

Hypersthene

Hypersthene ((Mg,Fe)SiO₃)

Small reddish-brown pebble, likely iron-rich rock or mineral fragment

Unidentified; possibly iron-oxide–stained quartz or ironstone

Sodalite

Sodalite, Na8(Al6Si6O24)Cl2

Polished dark stone fragment, possibly slate or schist

Fine-grained foliated metamorphic rock; exact mineral composition is indeterminate from the image

Weathered, iron-stained metamorphic rock (likely gneiss or schist)

Uncertain from the photograph; possibly quartz–feldspar–mica gneiss or schist

Biotite (Black Mica)

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

Geode

Silicon dioxide (Quartz/Chalcedony nodule)

Likely raw quartz-bearing stone, possibly greenish quartz or calcite

Uncertain from photograph; possible quartz (SiO₂) or calcite (CaCO₃)

Orange Calcite

Calcium Carbonate (CaCO3)

Iron-stained quartz-rich rock

Likely quartz with iron-oxide staining (SiO₂ with goethite/limonite); exact identification is uncertain from the photo

Brecciated Jasper

Microcrystalline Quartz (SiO2)

Feldspar (Plagioclase / Orthoclase)

KAlSi3O8 / CaAl2Si2O8 - NaAlSi3O8

Quartz Geode

Silicon Dioxide (SiO2)

Muscovite Mica

Muscovite: KAl2(AlSi3O10)(OH)2

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Quartz Geode

Silicon Dioxide (SiO2)

K-Feldspar Granite or Quartz

Potassium feldspar / Granite pegmatite

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

Yellow-green rough stone, possibly serpentine

Tentatively serpentine-group rock (serpentine minerals; composition and identity cannot be confirmed from the image)

Breccia

Breccia - Clastic sedimentary rock

Red coral beads (possibly dyed or imitation coral)

Corallium spp. skeleton, composed mainly of calcium carbonate (calcite); exact material cannot be confirmed from the image

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)

Smoky Quartz

Smoky Quartz (SiO2: Silicon Dioxide)

Likely quartz-rich stone or pale feldspar fragment

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

Sandstone

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

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

K-Feldspar (Potassium Feldspar)

KAlSi3O8

Quartz Geode

Silicon Dioxide (SiO2) in Host Rock

K-feldspar

Potassium Feldspar (Orthoclase/Microcline, KAlSi3O8)

Agate Geode

Silicon dioxide (Quartz), SiO2

K-Feldspar / Granite Pegmatite

Potassium Feldspar (Microcline/Orthoclase) with Quartz

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Likely tiger’s-eye rough fragment

Tiger’s-eye (quartz, SiO₂, with fibrous crocidolite-derived inclusions)

Pearl strand

Nacreous pearl, primarily aragonite (CaCO₃) with conchiolin protein

Mineral Specimen Collection (Galena, Quartz, Calcite, Hematite, etc.)

Mixed Mineral Assemblage (PbS, SiO2, CaCO3, Fe2O3, ZnS, etc.)