Igneous And Metamorphic Derivative (Weathered)

Weathered quartz-rich rock, possibly milky quartz in altered host rock

Milky quartz (SiO₂), with probable iron-oxide staining and a fine-grained host matrix

Iron-stained quartz-bearing rock, possibly weathered granite or gneiss

Quartz–feldspar rock with iron-oxide staining; exact identification requires testing

Weathered quartz-rich rock fragment

Likely quartz-bearing feldspathic fragment; exact identification requires testing

Small pink quartz pebble

Quartz, SiO₂; possibly rose quartz or pale chalcedony

Tumbled quartz pebble, likely iron-stained quartz

Quartz (silicon dioxide, SiO₂), possibly milky quartz with limonite/goethite staining

Small brown mineral fragment, possibly quartz/chert

Uncertain; likely microcrystalline quartz (SiO₂) or a weathered silicate rock

Quartz (Smoky/Granular variety)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Quartz (Grain)

Silicon Dioxide (SiO2)

Quartz with inclusions

SiO2

Mica Schist

Metamorphic rock predominantly composed of muscovite or biotite with quartz and feldspar

Granite or granitic pebble

Granite; chiefly quartz (SiO₂), feldspar, and mica/amphibole

Greenstone

Metabasalt (composed of chlorite, epidote, and actinolite)

Tumbled Clear Quartz/Rock Crystal

Silicon Dioxide (SiO2)

Fossilized shell fragment, likely bivalve

Bivalvia indet.; commonly preserved as calcite (CaCO₃) shell material

Quartz-rich weathered rock, possibly quartzite

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

Iron-stained milky quartz pebble

Quartz (SiO₂), commonly with iron-oxide staining

Weathered granite or granitic gneiss

Granite; mainly quartz (SiO₂), feldspar, and mica; possible weak gneissic texture

Weathered quartz-rich rock, possibly quartzite or granite fragment

Uncertain; likely quartz–feldspar aggregate, possibly altered granite or quartzite

Likely weathered fossil shell or fossiliferous limestone

Indeterminate molluscan fossil, possibly a bivalve or brachiopod preserved in carbonate rock

Auriferous Quartz (Gold-bearing Quartz)

Silicon Dioxide (SiO2) with trace Gold (Au) and Iron Oxides

Quartz-veined Metamorphic Pebble

Silicate-rich metamorphic rock with quartz veins (SiO2)

Small pale-yellow stone, likely quartz or quartz-rich pebble

Unidentified silica-rich specimen; possibly quartz (SiO₂)

Green sea glass or tumbled green quartz (uncertain)

Likely quartz (SiO₂) if natural; alternatively man-made soda-lime glass

Milky quartz pebble

Quartz, silicon dioxide (SiO₂)

Quartz vein with iron staining and dark sulfide/oxide minerals

Quartz (SiO₂), with probable iron oxides and unidentified dark sulfides

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Crystalline Silica (SiO2)

Rounded quartz-rich beach pebble

Likely milky quartz or quartzite (SiO₂)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Rounded gray stone, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; likely basalt (plagioclase ± pyroxene, possibly olivine)

Weathered schist or gneiss fragment

Quartz–feldspar–mica metamorphic rock; likely mica schist or gneiss

Likely weathered quartz-bearing rock (uncertain identification)

Possibly quartz-rich granite or granitic aplite; exact identification requires a clearer, larger image and tests

Quartz Pebble

Silicon Dioxide (SiO2)

Weathered quartz-rich rock, possibly quartzite or pegmatitic granite

Quartz (SiO₂) with probable feldspar and mica; exact rock identification is uncertain from the photograph

Rounded gray-green pebble, likely basaltic or metamorphic

Indeterminate mafic rock; possibly basalt, diabase, or greenstone

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Rounded granitic gneiss cobble

Foliated granitoid gneiss, chiefly quartz, feldspar, and mica

Weathered quartz-rich metamorphic rock, possibly quartzite or gneiss

Quartz-dominant silicate rock; likely quartz (SiO₂) with feldspar, mica, and minor iron-oxide staining