Identify any rockfrom a photo.

Coarse sand with a small pebble

Unconsolidated siliciclastic sediment, chiefly quartz and rock fragments

Likely calcareous concretions (limestone/chalk nodules)

Calcium-carbonate-rich sedimentary concretions, chiefly calcite (CaCO₃)

Chert (Jasper/Flint Pebble)

Microcrystalline Quartz (SiO2)

Rounded reddish-brown pebble, likely granite or granitic gneiss

Probable biotite-bearing granite (quartz, feldspar, and biotite); exact identification is uncertain from the image

Rounded quartzite pebble

Quartzite, composed predominantly of recrystallized quartz (SiO₂)

Chert (Flint / River Pebble)

Microcrystalline Quartz (SiO2)

Weathered mica-rich rock (tentative identification)

Possibly mica schist or phyllite; exact identification requires closer examination

Coarse-grained granite

Granite, chiefly quartz, feldspar, and mica

Rounded pebble, likely fine-grained river stone

Unidentified lithic pebble; composition cannot be determined from the image

Black-and-white patterned stone, possibly zebra marble

Uncertain from the image; likely calcite marble with dark mineral veining or inclusions

Likely iron meteorite fragment

Iron–nickel meteorite, probably kamacite with taenite; identification is uncertain from the photo alone

Pink granite

Granite, chiefly quartz, potassium feldspar, and plagioclase with minor mica