Mineral, Possibly Rock Fragment Containing A Mineral

Small weathered rock fragment

Indeterminate; possibly granitic or altered feldspathic material

Likely weathered stone or mineral fragment

Unidentified fine-grained silicate rock; possible basalt, greenstone, or serpentine

Concretion

Septarian concretion (likely containing Calcite or Siderite)

Sandstone or possibly a conglomerate

Arenite (if sandstone)

Dark volcanic rock, likely basalt

Basalt; fine-grained mafic silicate rock dominated by plagioclase and pyroxene, possibly with olivine

Unidentifiable embedded dark fragment

Indeterminate; possibly a dark silicate mineral or lithic inclusion

Likely pink feldspar-rich granite or pegmatite fragment

Uncertain from the image; possibly potassium feldspar (orthoclase/microcline) with quartz

Greenish quartz (likely prase/chalcedony)

Quartz, SiO₂; possibly green chalcedony or chlorite-included quartz

Uncertain small tan mineral/rock fragment

Indeterminate from image; possibly feldspar-rich rock or calcite

Small quartz-rich stone, possibly milky quartz or quartz-bearing rock

Quartz (SiO₂), identification uncertain from image

Quartz-rich hydrothermal vein rock, possibly quartzite

Mostly SiO₂ (quartz), with probable iron oxides and minor sulfides

Likely weathered quartz or feldspar grain

Uncertain; possibly quartz (SiO₂) or a feldspar mineral

Small brown-gray mineral fragment

Indeterminate; possibly weathered quartz-, feldspar-, or iron-oxide-bearing rock

Small white crystalline mineral fragment

Indeterminate; possibly calcite or quartz

Unidentified brown rock fragment

Not identifiable from the image; possibly iron-stained sandstone or another common weathered rock

Sandstone

Arenite (SiO2 based)

Small rounded quartz pebble

Quartz (SiO₂), possibly milky quartz

Pale greenish quartz-bearing rock, possibly serpentine or altered feldspar

Tentatively serpentinite-related rock (serpentine-group minerals) or altered granitic material; identification is uncertain from the photograph

Small metallic-looking mineral/rock fragment

Indeterminate from image; possible pyrite-bearing sulfide rock or native-metal/meteorite fragment

Small dark mineral/rock fragment

Indeterminate; possibly biotite-rich schist, graphite, or metallic sulfide

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Weathered granite or granitic gneiss

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

Weathered mafic rock, likely basalt

Basalt; predominantly plagioclase feldspar and pyroxene, possibly olivine and iron oxides

Small weathered mineral/rock fragment

Unidentified; likely quartz-rich material, possibly quartzite or feldspar-bearing rock

Small brown mineral fragment, possibly garnet

Unidentified; garnet is a tentative visual possibility (garnet-group silicates, X₃Y₂(SiO₄)₃)

Metallic sulfide mineral specimen, likely pyrite-bearing ore

Likely pyrite (FeS₂), possibly mixed with other sulfides or host rock

Small pale pebble, possibly quartz or feldspar

Unidentified silicate; appearance alone cannot distinguish quartz (SiO₂) from feldspar

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂), colored by hematite/goethite; possibly brecciated jasper

Greenish-gray rock fragment, likely serpentine-rich stone

Possibly serpentinite (serpentine-group minerals; identification is uncertain from the image)

Small tumbled orange-brown mineral fragment

Indeterminate; possibly iron-stained quartz, carnelian, or orange calcite

Likely weathered quartz-bearing rock fragment

Indeterminate; appears to contain quartz (SiO₂) with iron-oxide staining, possibly from quartzite, granite, or pegmatite

Small rounded mineral pebble, possibly quartz

Uncertain; likely microcrystalline or crystalline SiO₂ (quartz), potentially with iron-oxide staining

Iron-stained quartz-rich rock, possibly jasper or hydrothermal breccia

Microcrystalline quartz (SiO₂) with iron oxides/hydroxides, likely hematite and goethite; exact identification requires testing

Chert (Nodule / Geode fragment)

Microcrystalline Quartz (SiO2)

Iron-rich rock fragment, possibly limonite/goethite

Limonite (mixture of hydrated iron oxides, commonly goethite, FeO(OH))

Small pale mineral/rock fragment

Indeterminate; possibly weathered quartz, calcite, or light-colored limestone

Milky quartz (quartz-rich rock)

Quartz, silicon dioxide (SiO₂)

Weathered granitic rock fragment

Likely granite or granodiorite; quartz–feldspar–mica aggregate

Unknown dark mineral fragment

Indeterminate; possibly a dark silicate mineral or slag-like geological fragment

Unidentified brown rock fragment

Indeterminate from image; likely a weathered iron-rich lithic fragment

Small pale mineral fragment, possibly calcite

Unidentified; calcite (CaCO₃) is one possibility

Likely quartz-rich rock or mineral fragment

Quartz (SiO₂), possibly in a pegmatitic or granitic matrix