Igneous And Metamorphic Derivative (Weathered)

Orange Quartz

Silicon Dioxide (SiO2) with Hematite inclusions

Small rough mineral/rock fragment

Indeterminate; possibly quartz-bearing rock or weathered feldspar

Fossiliferous limestone (likely crinoidal or shell limestone)

Calcite-rich limestone; predominantly CaCO₃, with visible fossil fragments

Weathered foliated metamorphic rock, likely schist or gneiss

Micaceous schist/gneiss; composition likely quartz, feldspar, mica, and altered mafic minerals

Mixed rounded stream pebbles

Most appear to be granitic and mafic igneous rocks, including granite, gneiss, basalt, and possibly quartzite; exact identification is uncertain from the image.

Quartz-rich granitic cobble

Granite or granitic gneiss; primarily quartz, feldspar, and mica

Weathered quartz-rich pebble

Likely quartz-bearing granite or granitic gneiss; exact identification requires testing

Weathered basalt

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, with possible olivine and iron oxides

Pyrite-bearing Rock

Iron Sulfide (FeS2) associated with host rock

Rounded quartz-rich pebble

Quartz (SiO₂), possibly milky quartz or quartzite

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Quartz-rich rock fragment, possibly granite or quartzite

Primarily quartz (SiO₂), with possible feldspar and iron-oxide staining

Small rounded mineral pebble, possibly feldspar or quartz

Uncertain from image; likely a quartz- or feldspar-rich grain

Weathered granite or granitic metamorphic rock

Felsic granitoid, primarily quartz, feldspar, and mica; exact identification is uncertain from the photograph

Weathered foliated metamorphic rock, likely gneiss or schist

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

Rounded quartz-rich pebble

Likely milky quartz or quartzite (SiO₂), identification uncertain from image

Rounded quartz-rich pebble

Likely milky quartz or quartzite; SiO₂

Likely weathered quartz-rich pebble

Quartz (SiO₂), possibly iron-stained quartz or quartzite

Ruby / Pink Sapphire

Corundum (Al2O3 with Chromium impurities)

Tumbled milky quartz (likely quartzite or quartz pebble)

Quartz, silicon dioxide (SiO₂); exact rock type is uncertain from the image

Likely iron-stained quartz or feldspar fragment

Quartz (SiO₂) or potassium feldspar (KAlSi₃O₈), uncertain from image

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Corundum (Sapphire)

Corundum (Al2O3)

Milky Quartz with inclusions

Silicon Dioxide (SiO2)

Blue Sapphire

Corundum (Al2O3 with iron and titanium trace elements)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Polished granitic pebble

Granite, composed chiefly of quartz, feldspar, and mica/amphibole

Weathered metamorphic rock, possibly schist or gneiss

Indeterminate; likely quartz–feldspar–mica rock, potentially greenschist or gneiss

Quartz-rich stone tool or shaped mineral specimen

Likely milky quartz or quartzite (SiO₂); exact material cannot be confirmed from the image

Quartz Pebble

Silicon Dioxide (SiO2)

Coarse-grained granite or granitic gneiss

Granite; primarily quartz, potassium feldspar, plagioclase, and biotite/hornblende

Quartz Pebble

Silicon Dioxide (SiO2)

Feldspar (likely Orthoclase or Plagioclase)

Tectosilicate Feldspar (KAlSi3O8 to (Ca,Na)(Al,Si)4O8)

Sapphire

Corundum (Al2O3)

Weathered quartz-rich rock, possibly quartzite or granite

Indeterminate; likely quartz–feldspar aggregate, possibly granitic gneiss or quartzite

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz vein in host rock

Milky quartz (SiO₂), likely in a metamorphic host such as schist or gneiss

White quartz-rich rock, possibly milky quartz

Quartz (SiO₂), possibly quartzite or calcite-bearing material

Quartz-rich rock, possibly milky quartz or quartzite fragment

Quartz (SiO₂), potentially quartzite if metamorphic

Weathered quartz-rich cobble, possibly quartzite or feldspar-rich granite

Quartz–feldspar aggregate; identification is uncertain from the photograph

Weathered fossiliferous limestone, likely coral or shell fragment

Calcite (CaCO₃), biogenic limestone; exact fossil taxon indeterminate from the image