Sedimentary And Igneous (Mixed)

Gneiss (probable)

Quartz–feldspar–mica gneiss; exact mineral composition cannot be confirmed from the image

Decorative polished pebbles

Likely mixed quartz-rich lithologies, including quartzite, jasper, and/or basalt

Mixed rough mineral specimens, likely quartz-bearing rocks

Probable quartz (SiO₂), with possible feldspar, iron oxides, and altered host rock

Jasper

Microcrystalline Quartz (SiO2)

Migmatite

Migmatite (Mixed metamorphic-igneous rock)

Banded River Cobble with Mafic Dike

Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion

Aventurine (Green Quartz)

Silicon Dioxide (SiO2) with inclusions of Fuchsite (Mica)

Mixed rock collection

Labeled specimens appear to include iron-rich rock, schist, basalt, serpentinite, and shale

Granite (likely)

Coarse-grained felsic intrusive igneous rock, principally quartz and feldspar with dark mica or amphibole

Sodalite

Na8Al6Si6O24Cl2

Crushed Stone / Gravel

Aggregate (mixed lithology)

Gravel and Sediment Sample

Mixed clastic sediment

Limestone and Quartz Gravel with Petrified Wood

Sedimentary gravel aggregate and fossilized wood

River Rock

Mixed lithology clast

Mixed polished river stones

Likely quartz, quartzite, chert/jasper, and possibly limestone or marble

Silver-colored mica schist

Muscovite–quartz schist, possibly with biotite

Mixed rock specimens; likely breccia and quartz-bearing rocks

Indeterminate from the image; the brown, angular clasts may be breccia, with white quartz or calcite pieces nearby

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Quartz-rich rock, likely granite or quartz-bearing metamorphic rock

Undetermined; possibly granitic rock composed mainly of quartz and feldspar, with mica or other dark minerals

Small rock fragments; likely mixed local gravel, not identifiable to one species

Unidentified lithic fragments; individual rock types cannot be determined reliably from this photograph

Beach Pebbles and Shell Fragments

Polymictic Gravel and Bioclastic Sediments

Beach Pebbles and Quartz Aggregates

Quartz pebbles and biogenic fragments (SiO2, CaCO3)

Mixed gemstone jewelry collection

Various gemstone minerals, including likely amethyst (quartz), sapphire or iolite, garnet, pearl, turquoise, and colored beryl or tourmaline

Weathered quartz-rich pebble

Likely quartz-bearing granitoid or quartz-rich metamorphic rock; exact identification is uncertain from the image

Blue Calcite

Calcium Carbonate (CaCO3)

Mixed rock and mineral specimens

Predominantly quartz-rich rocks, with a possible malachite-bearing specimen; exact identification is uncertain from the image

Crocodile Jasper

Microcrystalline Quartz (SiO2)

Smoky Quartz with Feldspar

SiO2 (Quartz) with KAlSi3O8 (Feldspar)

River Pebbles

Polymictic Gravel

Coarse sand with a small pebble

Unconsolidated siliciclastic sediment, chiefly quartz and rock fragments

Mixed small mineral specimens, likely quartz varieties

Uncertain from the image; translucent pieces may be quartz (SiO₂), while golden-brown pieces could be iron-stained quartz or calcite

Dark gray weathered pebble, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

General river rock or weathered cobble

Mixed rock composition

Likely serpentinite (serpentine-rich rock)

Serpentinite, composed mainly of serpentine-group minerals (e.g., antigorite, lizardite, or chrysotile)

Assorted polished river pebbles

Mixed lithologies, likely quartzite, chert, jasper, and weathered igneous/metamorphic rocks

Polished mixed rock, likely orbicular/epidote-bearing granite or basalt

Uncertain; probable quartz–feldspar–amphibole/epidote aggregate

Rounded river pebbles, likely basalt and sandstone/conglomerate

Probable basalt (dark specimen) and ferruginous sandstone or weathered conglomerate (tan specimen)

Unidentified weathered rock fragments

Likely mixed silicate rocks; specific identification requires testing

African Jade

Grossular Garnet in massive rock matrix

Chakra Crystal Pendant

Mixed Quartz and Chalcedony (SiO2)

Red Jasper with Quartz Veining

Microcrystalline Quartz (SiO2)

Crushed Granite and Quartz Gravel

Composite Igneous and Silicate Rock Aggregate