Sedimentary And Igneous (Mixed)

Mixed tumbled stones

Mixed aggregate of quartz, chalcedony, jasper, feldspar, and other common silicate minerals

Arkosic Sandstone (or Conglomeritic Sandstone fragment)

Arkose (rich in feldspar)

Tumbled quartz-rich stone, possibly milky quartz or calcite

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

Assorted Tumbled Gemstones

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

Conglomeratic concrete or asphalt aggregate surface with dark bituminous chunks

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

Fossil Assortment and Geological Specimens

Various (including Ammonoidea)

Mixed Gemstone Bracelet

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

Gravel and Sand Aggregate

Unconsolidated Clastic Sediment

Mixed rounded river pebbles

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

Quartz-rich rock or quartz specimen

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

Mixed rock and mineral specimen collection

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

River Pebbles (including Granite and Basalt)

Mixed Igneous Rocks (Granite, Basalt)

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

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

Decorative polished pebbles

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

Migmatite

Migmatite (Mixed Rock)

Gravel or Crushed Stone

Fragmented Aggregate Stone

Mixed collection of natural stones

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

Aventurine (Green Quartz)

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

Mixed River Pebbles (including Unakite and Jasper)

Polymineralic geological specimens

Banded River Cobble with Mafic Dike

Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion

Mixed River Stones and Minerals

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

Mixed river-worn rock and mineral collection

Mostly quartz/quartzite, feldspar-bearing granitoid, chert, and mafic volcanic rocks; exact species vary by pebble

Mixed rock collection

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

Sodalite

Na8Al6Si6O24Cl2

Silver-colored mica schist

Muscovite–quartz schist, possibly with biotite

Mixed rough mineral specimens, likely quartz-bearing rocks

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

Migmatite

Migmatite (Mixed metamorphic-igneous rock)

Limestone and Quartz Gravel with Petrified Wood

Sedimentary gravel aggregate and fossilized wood

Crushed Stone / Gravel

Aggregate (mixed lithology)

Gravel and Sediment Sample

Mixed clastic sediment

Likely serpentinite (serpentine-rich rock)

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

Mixed polished river stones

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

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Beach Pebbles and Quartz Aggregates

Quartz pebbles and biogenic fragments (SiO2, CaCO3)

River Rock

Mixed lithology clast

Hematite cameo or hematine imitation

Hematite (Fe₂O₃); possibly synthetic hematine or black glass

Mixed gemstone jewelry collection

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

Smoky Quartz with Feldspar

SiO2 (Quartz) with KAlSi3O8 (Feldspar)

Dark gray weathered pebble, likely basalt

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

Crushed Granite and Quartz Gravel

Composite Igneous and Silicate Rock Aggregate