Mixed (Predominantly Sedimentary And Igneous)

Mixed rock and mineral collection

Multiple specimens; visible pieces may include quartz, calcite, agate/chalcedony, jasper, and dyed or coated materials

Quartz (Moss-covered)

Silicon Dioxide (SiO2)

Granite (likely)

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

Yellow Quartz

Silicon Dioxide (SiO2)

Dalmatian Stone (commonly called Dalmatian Jasper)

Peralkaline Rock (mixed Feldspar, Quartz, and Arfvedsonite)

Beach Pebbles and Quartz Aggregates

Quartz pebbles and biogenic fragments (SiO2, CaCO3)

Sodalite

Na8Al6Si6O24Cl2

Arkosic Sandstone (or Conglomeritic Sandstone fragment)

Arkose (rich in feldspar)

Garnet

Garnet (X3Y2(SiO4)3)

Gravel and Sediment Sample

Mixed clastic sediment

Limestone and Quartz Gravel with Petrified Wood

Sedimentary gravel aggregate and fossilized wood

Stream cobbles and gravel

Unidentified mixed fluvial clasts; likely quartzite, sandstone, and igneous/metamorphic fragments

Fluorite

Calcium Fluoride (CaF2)

Mixed Gemstone Bracelet

Mixed natural minerals and rocks (e.g., Rhodonite, Malachite, Sodalite, Rose Quartz, Black Tourmaline, Quartz/Chalcedony variants)

Gravel or Crushed Stone

Fragmented Aggregate Stone

River Rock

Mixed lithology clast

Mixed rounded river pebbles

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

Conglomeratic concrete or asphalt aggregate surface with dark bituminous chunks

Polymictic gravel aggregate; dark pieces likely bitumen/asphalt, not a natural 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

Carnelian

Carnelian (SiO2)

Amethyst and mixed gemstone bracelet

Amethyst: purple quartz, silicon dioxide (SiO₂); likely accompanied by other quartz or decorative mineral beads

Smoky Quartz with Feldspar

SiO2 (Quartz) with KAlSi3O8 (Feldspar)

Mixed rock collection

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

Coarse sand with a small pebble

Unconsolidated siliciclastic sediment, chiefly quartz and rock fragments

Assorted Tumbled Gemstones

Mixed oxides and silicates (including Quartz, Chalcedony, and Feldspar variants)

Mixed rock and mineral specimen collection

Varied silicate, carbonate, and oxide minerals; individual identification is not possible from this group photograph

Quartz-rich rock or quartz specimen

Quartz (SiO₂), likely massive quartz or quartz-bearing host rock

Decorative polished pebbles

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

Mixed rounded river pebbles, probably quartz-rich metamorphic and volcanic rocks

Predominantly quartzite/metachert, with possible rhyolite, sandstone, and iron-stained quartz; exact species cannot be determined confidently from the image

Mixed mineral and rock specimen collection with an obsidian-like centerpiece

Likely black obsidian (volcanic glass), alongside quartz, amethyst, agate/jasper, and other tumbled minerals

Banded River Cobble with Mafic Dike

Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion

Mixed rock and mineral specimen collection

Mostly undetermined from the photograph; apparent quartz-rich rocks, sandstone, granite/gneiss, and possibly iron-oxide-bearing specimens

Mixed rock and mineral specimen collection

Multiple species, likely quartz (SiO₂), calcite (CaCO₃), feldspar, chert, and assorted volcanic/sedimentary rocks

Gneiss (probable)

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

Dalmatian Jasper

Aplite with Arfvedsonite inclusions

Dark gray weathered pebble, likely basalt

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

Mixed collection of natural stones

Several unidentified lithologies, likely including basalt, granite, quartzite, sandstone, and weathered metamorphic rocks

Tumbled quartz-rich stone, possibly milky quartz or calcite

Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing

Quartz pebble

Silicon dioxide (SiO2)

Beach Pebbles and Jasper

Quartz / Microcrystalline Silicon Dioxide (SiO2)

Mixed River Stones and Minerals

Mixed Silica-rich Stones (Quartz, Agate, Jasper, Sandstone, Dalmation Stone)

Crushed Granite and Quartz Gravel

Composite Igneous and Silicate Rock Aggregate