Metamorphic, Likely Sedimentary With Quartz Veins

Black-and-white banded pebble (likely gneiss or migmatite)

Undetermined banded metamorphic rock; mineral composition cannot be confirmed from the image

Iron-rich metamorphic rock (probable limonite/goethite-bearing schist)

Quartz–mica schist with iron oxyhydroxides, chiefly goethite (FeO(OH)) and limonite (amorphous hydrated iron oxides)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Pyrite-bearing metamorphic rock (probable pyrite schist or sulfide ore)

Pyrite (FeS₂) in a foliated, quartz–mica-rich host rock; exact identification requires testing

Pyrite in Matrix (likely Quartz or Schist matrix)

Iron Sulfide (FeS2)

Likely rose quartz fragment

Quartz (SiO₂), likely pale rose quartz

Vein-bearing sandstone or quartzite cobble

Quartz-rich sandstone with white quartz veins; possibly metamorphosed to quartzite

Quartz-rich river pebble (likely milky quartz or quartzite)

Quartz, SiO₂; possibly quartzite, a metamorphic rock dominated by quartz

Quartz Vein in Siltstone

SiO2 (Quartz) on clastic sedimentary matrix

Quartz pebble or quartz-rich fragment

Quartz (silicon dioxide, SiO₂), possibly iron-stained or included

Small white rounded mineral grain, likely quartz

Quartz (SiO₂), probable milky or vein quartz

Likely milky quartz or white calcite

Quartz (SiO₂) or calcite (CaCO₃); identification is limited by the photograph

Rough Quartz (likely Rose or Smoky variant)

Silicon Dioxide (SiO2)

Quartz vein in host rock

Quartz (SiO₂) vein cutting an unidentified, likely metamorphic host rock

Quartz / Quartzite Fragment

Silicon Dioxide (SiO2)

Weathered quartz-rich rock, possibly quartzite or granite fragment

Quartzite (SiO₂) or quartz-bearing granitoid; exact identification requires testing

Quartz fragment (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Iron-stained brecciated quartz/quartzite

Quartz-rich breccia; predominantly SiO₂ with iron-oxide/hydroxide coatings (goethite/limonite)

Likely calcite fragment

Calcite (calcium carbonate, CaCO₃)

Red jasper in a gray host rock (likely jasperized volcanic rock)

Microcrystalline quartz (SiO₂), iron-oxide–colored jasper, in a fine-grained volcanic or sedimentary matrix

Veined gneiss

Felsic to mafic banded gneiss, chiefly quartz–feldspar–biotite/hornblende

Yellow quartz pebble

Quartz (SiO₂), likely iron-stained or naturally yellow quartz; exact variety cannot be determined visually

Weathered quartz-bearing rock fragments

Likely quartz (SiO₂) in a weathered iron-stained host rock; exact identification is uncertain from the image

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Quartz-bearing metamorphic rock, likely quartzite with dark mica/amphibole

Quartzite or quartz-rich schist; chiefly SiO₂ quartz with biotite, hornblende/amphibole, and iron-oxide staining

Weathered quartz-rich rock, possibly milky quartz or quartzite

Quartz (SiO₂), likely with iron-oxide staining and minor host minerals

Quartz-rich sandstone or quartzite pebble

Likely quartz arenite sandstone; possibly low-grade quartzite, composed mainly of SiO₂

Quartz crystal cluster

Quartz (silicon dioxide, SiO₂), likely milky or included quartz

Quartz-veined dark metamorphic rock, likely schist or gneiss

Quartz-bearing mica schist/gneiss; mainly quartz (SiO₂), feldspar, mica, and iron-oxide staining

Quartz (Milky/Cloudy Variety)

Silicon Dioxide (SiO2)

Weathered quartz-rich rock, possibly quartzite or quartz vein material

Quartz-dominant aggregate; chiefly SiO₂, with likely iron-oxide staining and minor feldspar or mica

Small quartz fragment, possibly milky quartz

Quartz (SiO₂)

Carved yellow calcite (likely honey/orange calcite)

Calcite, calcium carbonate (CaCO₃)

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Weathered quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂); possibly quartzite, a metamorphosed quartz sandstone

Rounded quartz-veined pebble

Likely quartz-veined metamorphic rock; exact host rock is indeterminate from the image

Quartz with impurities or Host Rock

SiO2 (Silicon Dioxide) with mixed silicates

Mixed Mineral Collection

Multi-mineral Assemblage (Quartz, Jasper, Obsidian, Pyrite, etc.)

Pyrite-bearing rock

Likely pyrite (FeS₂), possibly with quartz or other sulfide minerals

Milky quartz-rich vein rock (likely quartzite or silicified host rock)

Quartz, SiO₂; possibly quartzite with iron-oxide and minor feldspar/clay inclusions

Slate with Quartz

Low-grade Metamorphic Slate with SiO2 inclusions

Milky quartz-rich rock, possibly quartzite

Quartz (SiO₂), likely in a quartzite or quartz-vein matrix