Mixed (Sedimentary, Igneous, And Metamorphic)

Feldspar

Feldspar (Orthoclase/Microcline)

Blue Apatite

Ca5(PO4)3(F,Cl,OH)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Weathered metallic sulfide-bearing rock, possibly pyrite-rich ore

Tentatively pyrite (FeS₂) with iron oxides and host rock; exact identification requires testing

Conglomeratic gravel / polymictic breccia

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

Zoisite with Hornblende

Zoisite (Ca2Al3(SiO4)3(OH)) with Amphibole inclusions

Mixed tumbled stone collection

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

Granite with Epidote

Granite, containing quartz, feldspar, and epidote

Tumbled mixed mineral specimens, likely quartz-rich rocks

Predominantly quartz (SiO₂), with possible jasper, agate, feldspar, and iron-oxide minerals

Hematite

Hematite (Α-Fe2O3)

Magnetite Ore

Magnetite (Fe3O4)

Fossiliferous Limestone

Limestone (CaCO3 with Limonite/Goethite staining)

Red porphyritic volcanic rock, likely rhyolite or andesite

Porphyritic rhyolite–andesite; predominantly quartz/feldspar with iron-oxide staining

Tumbled metallic sulfide mineral specimen, likely pyrite-bearing ore

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

Yellow Jasper

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

Tumbled Carnelian and Quartz Mix

Silicon Dioxide (SiO2) with iron oxide impurities

Pink Granite

Felsic Plutonic Rock (Granite)

Weathered granite pebble

Granite, predominantly quartz–feldspar–mica aggregate

Mahogany Obsidian

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

Black tourmaline bead bracelet

Schorl tourmaline, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Tumbled orbicular granite

Granite, commonly biotite–quartz–feldspar granite with orbicular or mafic enclaves

Pyrite

Iron Sulfide (FeS2)

Black Tourmaline

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Concrete with Aggregate

Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)

Magnetite

Iron(II,III) oxide (Fe3O4)

Weathered iron-rich rock, possibly hematite-bearing breccia

Hematite (Fe₂O₃)-rich lithic fragment; exact host rock is uncertain from the image

Pegmatite with Quartz and Feldspar

Intrusive Igneous Rock

Tumbled emerald chips

Emerald, green beryl (Be₃Al₂Si₆O₁₈), colored mainly by chromium and/or vanadium

Pea Gravel / River Gravel

Unconsolidated Clastic Sedimentary Aggregate

Magnetite / Ironstone

Magnetite (Fe3O4)

Black Tourmaline

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Jadeite and Mixed Gemstones (Ruby, Sapphire, Emerald)

Jadeite (NaAlSi2O6), Corundum (Al2O3), Beryl (Be3Al2(Si6O18))

Weathered polymictic rock fragment, likely granite-rich conglomerate

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

Moonstone

Orthoclase (KAlSi3O8) or Oligoclase with adularescence

Mixed limestone and sandstone specimens

Mostly calcitic limestone (CaCO₃), with possible quartz-rich sandstone and iron-oxide staining

Mixed gravelly conglomeratic road aggregate

Polymictic clast-supported conglomerate or fill; composition varies, commonly quartz, feldspar, basalt, and weathered rock fragments

Mixed river gravel, prominently iron-stained chert/jasper

Microcrystalline quartz (SiO₂), chiefly chert/jasper with iron-oxide staining; mixed clasts may include quartzite and other silicates

Jasper and Mixed River Pebbles

Microcrystalline Quartz (Chalcedony / Jasper)

Mixed rock fragments, likely basalt and weathered granite

Probable mafic volcanic rock (basalt) with granitoid fragments; exact identification is uncertain from the image

Mixed rounded cobbles, likely granite and weathered volcanic rock

Granite and probable andesite/basalt clasts; exact identification is uncertain from the photograph

Quartz vein fragment

Quartz, silicon dioxide (SiO₂), likely milky to translucent quartz with iron-oxide or clay inclusions