Metamorphic, Likely Sedimentary With Quartz Veins

Quartz with Iron Oxide

SiO2

Tumbled blue stone and polished red-brown stone

Likely sodalite or blue aventurine; red specimen possibly jasper or polished flint/chert

White quartz pebble

Quartz (silicon dioxide, SiO₂)

Milky quartz (likely quartz fragment)

Quartz, silicon dioxide (SiO₂)

Rounded quartz-rich pebble, likely quartzite or quartz sandstone

Quartzite (mostly SiO₂), possibly ferruginous quartz sandstone

Mixed polished gemstones and minerals

Likely agate/chalcedony (SiO₂), quartz, jasper, and possibly aventurine or obsidian; exact identification requires individual testing.

Tumbled white quartz pebble

Quartz, silicon dioxide (SiO₂), likely milky quartz

Weathered metallic sulfide fragment, possibly pyrite-bearing rock

Likely iron sulfide (pyrite, FeS₂) in a weathered host rock; exact identification requires testing

Quartz-rich pegmatitic rock, probably granitic gneiss

Quartz–feldspar–mica gneiss; locally pegmatitic granite

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Milky quartz with dark mineral veins

Quartz, silicon dioxide (SiO₂), likely massive vein quartz; dark veins may be chlorite, mica, iron/manganese oxides, or a sulfide mineral

Milky Quartz in Matrix

Silicon Dioxide (SiO2)

Quartz

Silicon dioxide (SiO2)

Small quartz-rich rock fragment (tentative)

Likely quartz (SiO₂) with possible feldspar or carbonate inclusions

Tumbled quartz-rich pebble, likely quartzite or chert

Quartz (SiO₂), possibly quartzite; exact identification is uncertain from the image

Quartz (Milky/Common Quartz)

Silicon Dioxide (SiO2)

Yellow Chalcedony (Agate/Chert)

Cryptocrystalline Quartz (SiO2)

Milky quartz pebbles

Quartz (silicon dioxide, SiO₂)

Veined marble or calcitic limestone

Calcite-dominant carbonate rock (CaCO₃), likely marble

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Quartz-rich pegmatite or quartz vein fragment

Massive to coarse-grained quartz (SiO₂), likely with feldspar and minor mica

Quartz vein in dark metamorphic rock

Likely quartz-rich vein cutting a biotite- or amphibole-rich metamorphic host; exact host rock cannot be confirmed from the image

Likely slate fragments

Slate, a fine-grained metamorphic rock composed chiefly of quartz, mica, and chlorite

Rounded quartz-rich pebble

Massive quartz (silicon dioxide, SiO₂), possibly milky quartz or quartzite

Uncertain gray metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica rock; exact identification requires close examination

Quartz (Milky Quartz / Quartzite)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Emerald with Matrix (Emerald in Mica Schist)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Quartz-rich weathered rock, possibly quartzite

Quartzite (mostly SiO₂); exact identification is uncertain from the image

Coarse-grained granite

Granite; predominantly quartz, potassium feldspar, plagioclase, and biotite/hornblende

Weathered quartz-rich metamorphic rock

Likely quartzite or quartz-veined metamorphic rock, chiefly SiO₂ with iron-oxide staining

Veined dark metamorphic rock, likely serpentinite

Serpentinite, predominantly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with possible quartz, calcite, and magnetite veins

Clear Quartz (Rock Crystal) Bracelet

Silicon Dioxide (SiO2)

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Epidote in Matrix (likely Amphibolite or Gneiss)

Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)) in Metamorphic Matrix

Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image)

Quartz (SiO₂ - Silicon Dioxide)

Milky quartz with iron-oxide staining

Quartz, silicon dioxide (SiO₂)

Quartz / Limestone Gravel

SiO2 (Silicon Dioxide) and CaCO3 (Calcium Carbonate)

Tumbled quartz pebble

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