Igneous And Metamorphic Derivative (Weathered)

Sapphire

Corundum (Al2O3)

White Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Weathered, iron-stained metamorphic rock (probable schist or gneiss)

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and thin-section or mineral tests

Weathered quartz-mica schist

Quartz–muscovite/biotite schist, locally iron-oxide stained

Quartz (Iron-Stained Quartz Pebble)

Silicon Dioxide (SiO2)

Quartz Sand

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble (Chalcedony / Milky Quartz)

Silicon Dioxide (SiO2)

Mixed Rock Collection (Pebbles and Stones)

Various geological specimens

Clear Quartz

Silicon Dioxide (SiO2)

Quartz (Granular)

Silicon Dioxide (SiO2)

Milky quartz with iron staining

Quartz, silicon dioxide (SiO₂)

Weathered granite or granitic gneiss fragment

Quartz–feldspar–mica aggregate; likely granite (possibly gneiss)

Milky quartz (rough quartz specimen)

Quartz, silicon dioxide (SiO₂)

Weathered quartz-rich metamorphic rock, likely quartzite or gneiss

Quartzite/gneiss; chiefly quartz (SiO₂) with feldspar and mica/iron oxides

Weathered granitic rock

Granite or granodiorite; primarily quartz, feldspar, and mica

Milky quartz with iron-oxide staining

Quartz (SiO₂), likely massive or vein quartz

Weathered volcanic rock, likely vesicular basalt or scoria

Basaltic volcanic rock; predominantly plagioclase, pyroxene, and possibly olivine with iron-oxide weathering

Mixed rounded river pebbles

Polymictic alluvial gravel; likely quartz/quartzite, chert, and weathered feldspathic rocks

Small quartz-rich rock fragment (tentative)

Quartz, silicon dioxide (SiO₂), possibly in a feldspar-bearing granite fragment

Milky quartz (quartz-rich rock)

Quartz, silicon dioxide (SiO₂)

Gold Nugget / Placer Gold

Native Gold (Au)

Quartz-rich feldspathic rock, possibly granite or pegmatite fragment

Granite/pegmatite; chiefly quartz (SiO₂), feldspar, and minor dark mica or amphibole

Weathered quartz-rich pegmatite, likely feldspar/quartz

Granitic pegmatite; chiefly microcline or plagioclase feldspar (KAlSi₃O₈–NaAlSi₃O₈) with quartz (SiO₂), possibly mica

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon dioxide (SiO2)

Milky quartz vein fragment

Quartz, silicon dioxide (SiO₂)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Possible weathered basalt or iron-rich slag

Basalt, tentatively; composition likely plagioclase and pyroxene with possible magnetite

Weathered granite or granitic pegmatite fragment

Felsic intrusive rock composed mainly of quartz, feldspar, and minor mica

Likely quartz-bearing metamorphic pebble

Indeterminate; probable quartzite or quartz-rich gneiss with dark mica/amphibole

White quartz-rich pebble

Likely quartzite or milky-quartz pebble (SiO₂)

Milky quartz vein fragment

Quartz (silicon dioxide, SiO₂), massive or granular variety

Quartz (Raw and Water-worn)

Silicon Dioxide (SiO2)

Unidentified dark, foliated metamorphic rock

Likely biotite schist or hornblende-bearing gneiss; exact identification requires testing

Banded gneiss

Gneiss, commonly quartz–feldspar–mica assemblage

Quartz-rich pegmatitic rock, possibly altered granite

Quartz–feldspar pegmatite; probable composition of quartz (SiO₂), feldspar, and mica/secondary alteration minerals

Weathered dark stone, possibly basalt

Basalt; commonly plagioclase feldspar, pyroxene, and minor olivine

Massive quartz (milky quartz), possibly quartz-rich mineral aggregate

Quartz, silicon dioxide (SiO₂)