Mixed (Predominantly Sedimentary And Igneous)

Tumbled quartz-rich stone, possibly granite or rhyolite

Likely quartz (SiO₂) with feldspar and minor mica or other inclusions

Crushed granite aggregate

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, alkali feldspar, plagioclase, and minor mica/amphibole

Tumbled granite or granitic gneiss pebble

Granite/granitic gneiss, chiefly quartz, feldspar, and dark biotite or amphibole

Granite

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

Asphalt (Bituminous pavement)

Bituminous concrete / Asphalt

Mixed pebble collection, including likely flint, quartzite, and fossil material

Varied silicate rocks; visible specimen may include chert (microcrystalline SiO₂), quartzite, and a possible fossil

Mixed landscaping gravel and rounded fieldstones

Lithologically mixed aggregate; likely quartzite, basalt, granite, and weathered sedimentary rocks

Likely gray granite fragment

Granite, composed mainly of quartz, feldspar, and mica

Graywacke (River Cobble)

Graywacke (Lithic Sandstone)

Yellow Chert (Chert / Jasper)

Silicon Dioxide (SiO2 / Microcrystalline Quartz)

Gneiss (likely garnet-bearing)

Banded orthogneiss/paragneiss; chiefly quartz, feldspar, biotite and amphibole, with possible garnet

Gabbro

Gabbro

Pink Granite

Granite (Felsic Plutonic Igneous Rock)

Weathered sandstone or quartz-rich sedimentary rock

Likely quartz arenite or feldspathic sandstone; exact identification requires testing

Sandstone (Common Quartz Pebble/Rock)

Sedimentary rock / Quartz arenite

Granite

Intrusive Igneous Rock

Green-and-gold apatite-bearing rock, possibly epidote skarn

Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F), with probable epidote and quartz; exact identification requires testing

Serpentinite

Serpentinite (composed mainly of serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)

Fossiliferous limestone (likely crinoidal or shell limestone)

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

Polished labradorite-bearing rock

Labradorite, a calcium-rich plagioclase feldspar; likely mixed with quartz and mafic minerals

Sandstone

Quartz Sandstone (predominantly)

Banded gneiss (likely garnet-biotite or quartz-feldspar gneiss)

Gneiss; predominantly quartz (SiO₂), feldspar, and dark biotite/amphibole

Mixed polished gemstone and mineral collection

Primarily quartz varieties (SiO₂), plus probable aventurine, rose quartz, amethyst, agate, jasper, serpentine, feldspar, and possibly dyed or man-made glass pieces

Epidote in Granite Gneiss

Epidote bearing Orthogneiss (Ca2(Al,Fe)3(SiO4)3(OH))

Mixed rounded river pebbles, likely basalt and granite

Basalt (fine-grained mafic rock) and granite/granitoid (quartz–feldspar rock)

Weathered polymictic rock fragment, likely granite-rich conglomerate

Indeterminate mixed lithology; apparent granitic clasts containing quartz, feldspar, and dark mafic minerals

Conglomeratic gravel / polymictic breccia

Polymictic rudite, likely anthropogenic or beach/stream gravel; composition varies

Polished pink-and-gray stone, possibly granite or rhyolite

Probable felsic igneous rock; likely quartz–feldspar–mica aggregate, but exact identification is uncertain from the image

Pyrite-bearing sulfide specimen

Pyrite (FeS₂), possibly mixed with chalcopyrite or other iron sulfides

Tumbled metallic sulfide mineral specimen, likely pyrite-bearing ore

Likely pyrite (FeS₂) with associated sulfides and host rock; exact identification requires testing

Tumbled yellow-brown jasper

Jasper, microcrystalline quartz (SiO₂) with iron-oxide impurities

Fuchsite Schist

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2) in Schist

Mixed tumbled gemstone and mineral lot

Primarily quartz varieties (SiO₂), feldspar, beryl/chalcedony, and other unidentified silicate minerals

Mixed tumbled stone collection

Assorted minerals, likely including quartz, jasper, agate, and possibly obsidian or hematite

Blue Topaz (Cut Gemstone)

Aluminum silicate fluoride hydroxide (Al2SiO4(F,OH)2)

Tumbled Carnelian and Quartz Mix

Silicon Dioxide (SiO2) with iron oxide impurities

Tumbled jasper or chalcedony pebble

Microcrystalline quartz (SiO₂), likely jasper/chalcedony with iron-oxide staining

Likely amphibolite

Amphibolite, composed chiefly of hornblende and plagioclase feldspar

Fossiliferous Limestone

Limestone (CaCO3 with Limonite/Goethite staining)

Yellow Jasper

Silicon Dioxide (SiO2) with hydrated iron oxide impurities (Goethite)

Pink Granite

Felsic Plutonic Rock (Granite)

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions (SiO2 + Fe2O3)