Metamorphic Or Sedimentary (With Staining)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble

Silicon dioxide (SiO2)

Quartzite River Rock

Quartzite (SiO2)

Tumbled quartz-rich pebble, likely quartzite or chert

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

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz

Silicon Dioxide (SiO2)

Likely rough quartz with iron-oxide staining

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

Quartz

Silicon dioxide (SiO2)

Foliated metamorphic rock (likely mica schist)

Mica schist, probably quartz–muscovite/biotite schist; exact identification requires close inspection

Banded gneiss

Quartzo-feldspathic biotite gneiss, possibly garnet-bearing

Exposed aggregate concrete (stone-chip surface)

Portland-cement concrete containing natural aggregate; not a natural rock

Weathered, iron-stained rock (likely sandstone or breccia)

Indeterminate clastic sedimentary rock; possible ferruginous sandstone or weathered breccia

Quartz (Milky Quartz / Quartzite)

Silicon Dioxide (SiO2)

Quartz (Milky/Iron-stained)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Weathered iron-stained quartzite or jasper

Quartzite dominated by quartz (SiO₂), with iron oxides/hydroxides such as hematite and limonite

Rounded brown river pebble

Indeterminate; likely weathered sandstone or iron-stained quartzite

Jasper

Silicon dioxide (SiO2) with impurities

Quartz (Iron-stained or Milky)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Weathered quartz-rich rock, possibly sandstone or quartzite

Indeterminate; likely quartz sandstone (SiO₂-rich), possibly weakly metamorphosed quartzite

Pyritic Quartzite

Quartzite with Pyrite inclusions (FeS2)

Weathered quartz-rich rock fragment

Likely milky quartz–bearing quartzite or silica-rich chert; exact identification requires testing

Quartz (Citrine or Iron-Stained)

SiO2

Pyrite in Matrix (Healers Gold / Pyrite Egg)

Iron Disulfide (FeS2) with Magnetite/Hematite matrix

Yellow-orange quartz/chalcedony pebble (possibly citrine-bearing)

Quartz, SiO₂; likely microcrystalline chalcedony with iron staining

Quartz

Silicon Dioxide (SiO2)

Weathered quartz-rich rock, likely chert or quartzite

Microcrystalline quartz (SiO₂), possibly with iron-oxide staining

Milky Quartz

Silicon Dioxide (SiO2)

Biotite-bearing schist (likely mica schist)

Mica schist, commonly quartz + biotite ± muscovite; composition varies

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂), possibly with feldspar, mica, and iron-oxide impurities

Quartz (Common or Milky)

Silicon Dioxide (SiO2)

Iron-stained Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite inclusions

Blue apatite (likely dyed or enhanced)

Apatite group; fluorapatite, Ca5(PO4)3F, is the common blue variety

Muscovite Schist

Mica Schist (primarily KAl2(AlSi3O10)(OH)2)

Weathered quartz-rich rock, possibly quartzite or sandstone

Likely quartzite (mostly SiO₂), though heavily weathered sandstone is possible

Tiny rounded metallic-looking pebble, possibly pyrite or a metal-rich mineral

Uncertain from image; possible pyrite (FeS₂), chalcopyrite (CuFeS₂), or magnetite (Fe₃O₄)

Weathered quartz-rich metamorphic rock (probable gneiss or quartzite)

Biotite–quartz–feldspar gneiss, possibly micaceous quartzite

Dark gray slate (possibly argillite or shale)

Slate, a low-grade metamorphic rock derived mainly from shale; composition commonly quartz, illite/muscovite, chlorite, and clay minerals

Quartz

Silicon dioxide (SiO2)