Metamorphic Or Sedimentary (With Staining)

Gneiss

Metamorphic rock of high-grade regional metamorphism

Ferruginous Quartzite (Chert)

Quartzite with Iron inclusions (SiO2 + Fe2O3)

Weathered gneissic rock

Biotite–quartz–feldspar gneiss, possibly migmatitic

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Milky Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Weathered quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide staining

Tumbled quartz pebble (likely milky quartz or chalcedony)

Quartz, SiO₂; possibly microcrystalline quartz (chalcedony)

Gneiss with Iron Staining and Sulfide Mineralization

Metamorphic Gneiss / Amphibolite with Iron/Sulfide Oxidation

Quartz (Yellow / Citrine Quartz Pebble)

Silicon Dioxide (SiO2)

Weathered quartz-rich rock, likely arkose or quartzite

Quartz-dominant siliciclastic rock; probable arkose (quartz + feldspar), possibly weakly metamorphosed quartzite

Weathered quartz-rich rock, likely sandstone or quartzite

Quartz (SiO₂)-rich sandstone; possibly partially metamorphosed quartzite

Agate

Silicon Dioxide (Chalcedony), SiO2

Quartz-rich pegmatitic rock, probably granitic gneiss

Quartz–feldspar–mica gneiss; locally pegmatitic granite

Quartz

Silicon Dioxide (SiO2)

Quartz (Iron-stained or Chalcedony varieties)

Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Weathered quartz-bearing metamorphic rock, likely gneiss or quartzite

Quartz-rich gneiss/quartzite with feldspar, mica, and iron-oxide alteration

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Quartz-rich rock, likely milky quartz with iron staining

Quartz (SiO₂), possibly quartzite or quartz vein material

Weathered iron-stained quartzite or chert nodule

Siliceous rock composed chiefly of microcrystalline quartz (SiO₂), with iron-oxide staining and possible clay/minor carbonate minerals

Quartz (Raw / Unpolished)

Silicon Dioxide (SiO2)

Polished gray pebble, likely quartzite or chert

Quartzite (mostly SiO₂), tentative identification

Quartz-rich river pebble, possibly weathered quartzite

Quartzite; predominantly crystalline SiO₂, though exact identification is uncertain from the photograph

Quartz

Silicon Dioxide (SiO2)

Iron-rich quartzite or ironstone fragment

Quartzite dominated by quartz (SiO₂), with iron oxides such as hematite/goethite

Gneiss with Quartz Veining

Gneiss (High-grade Metamorphic Rock)

Tumbled quartz-rich pebble, possibly citrine or iron-stained quartz

Quartz, silicon dioxide (SiO₂), with probable iron-oxide inclusions

Tumbled quartz-rich stone, likely iron-stained quartzite

Quartzite; predominantly microcrystalline SiO₂ with iron-oxide staining

Slate or strongly foliated schist

Metamorphosed shale; commonly muscovite–quartz–chlorite schist or slate

Quartz pebble with a conchoidal chip

Silicon dioxide (SiO2)

Banded gneiss cobble

Gneiss, commonly quartz–feldspar–mica gneiss

Banded gneiss (likely weathered orthogneiss)

Gneiss; predominantly quartz–feldspar–mica, with possible iron-oxide staining

Schist

Metamorphic Rock (Schist)

Iron-stained quartz pebble

Quartz (SiO₂), likely microcrystalline or massive quartz with goethite/limonite staining

Sandstone or Quartzite pebble

Sandstone (Quartz arenite) or Quartzite

Iron-stained metamorphic rock, likely quartzite or jasper

Quartz-rich rock dominated by SiO₂, with iron oxides/hydroxides (hematite, goethite) and possible clay or mica

Clear quartz chips

Quartz (silicon dioxide, SiO₂)

Calcite

Calcium Carbonate (CaCO3)

Quartz-rich metamorphic rock, likely quartzite

Quartzite, composed predominantly of quartz (SiO₂), with minor iron-oxide staining and possible feldspar/mica

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz-rich river pebble, likely milky quartz

Milky quartz (SiO₂), possibly a quartzite or quartz-rich silicate pebble