Metamorphic Or Sedimentary

Banded gneiss

Gneiss, commonly quartz–feldspar–mica gneiss

Small quartz-rich mineral fragment

Quartz (SiO₂), possibly milky or chalcedonic quartz

Quartz vein fragment

Quartz, silicon dioxide (SiO₂), likely milky to translucent quartz with iron-oxide or clay inclusions

Quartz-rich rock, possibly milky quartz or quartzite

Quartz (SiO₂); if quartzite, recrystallized quartz sandstone

Tumbled quartz pebble, possibly citrine or pale smoky quartz

Quartz (SiO₂), likely microcrystalline/tumbled material

Unidentified greenish-gray rock fragment

Tentatively altered basalt or basaltic volcanic rock; mineral identification requires testing

Vesicular basalt with secondary mineralization

Mafic volcanic rock, chiefly plagioclase and pyroxene, with iron oxides and likely zeolite/calcite infillings

Likely weathered quartz-bearing rock (uncertain identification)

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

Dark gray rock fragment, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with minor olivine and magnetite

Dark gray volcanic rock, probably andesite or basalt

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

Dark rock specimen (possibly slate or shale)

Unidentified fine-grained rock; slate is foliated metamorphosed shale, while shale is sedimentary mudrock

Quartz

Quartz (SiO2 - Silicon Dioxide)

Quartzite

Metamorphic Quartzite (primarily SiO2)

Quartz Heart or Arrowhead Shape

Silicon Dioxide (SiO2)

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Quartz

Quartz (SiO₂)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (SiO2)

Quartz (likely Rose Quartz or Milky Quartz based on color)

Quartz (SiO2 - Silicon Dioxide)

Quartz (pebble)

Quartz (SiO₂)

Tumbled quartz-rich pebble, likely quartzite or chert

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

Milky Quartz

Silicon dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Likely quartz-bearing rock fragment

Quartz (SiO₂), possibly with iron-oxide staining or other mineral inclusions

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Likely rough quartz with iron-oxide staining

Quartz (SiO₂), possibly with iron-oxide inclusions or surface staining

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (Smoky/Milky variety)

Silicon Dioxide (SiO2)

Red Jasper

Microcrystalline Quartz (Chalcedony), SiO2

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)