Mixed

Pegmatitic granite

Quartz–feldspar–mica granite pegmatite

Likely amphibolite

Amphibolite, composed chiefly of hornblende and plagioclase

Chrysocolla-rich copper ore

Chrysocolla, a hydrated copper silicate; composition is variable and commonly mixed with quartz or copper oxides

Rounded weathered stone, likely basaltic or volcanic rock

Indeterminate fine-grained mafic volcanic rock; possibly basalt or andesite

Silver-colored mica schist

Muscovite–quartz schist, possibly with biotite

Quartz with Feldspar

Silicon Dioxide (SiO2) with Potassium Feldspar (KAlSi3O8)

Unakite (Epidotized Granite)

Epidotized Granite (mixture of Orthoclase, Epidote, and Quartz)

Pink granite (likely weathered granite)

Granite, a coarse-grained felsic intrusive igneous rock, composed mainly of quartz, feldspar, and mica

Tumbled jasper or chalcedony pebble

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

Polished black stone, likely obsidian or dark basalt

Volcanic glass (obsidian), possibly basalt; exact identification requires testing

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

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

Tumbled jasper (likely brecciated or red jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide inclusions

Fuchsite on Quartz

Muscovite (KAl2(AlSi3O10)(OH)2) with Chromium impurities

Conglomeratic gravel / polymictic breccia

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

Weathered conglomeratic breccia

Polymictic conglomerate/breccia, likely iron-stained

Iron-rich meteorite candidate (possibly stony-iron meteorite)

Unclassified meteoritic material; apparent Fe-Ni metal with silicate matrix

Goldstone

Avventurina (Man-made Glass with Copper inclusions)

Tumbled metallic sulfide mineral specimen, likely pyrite-bearing ore

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

Glass / Silicon Dioxide (Man-made)

SiO2 (Amorphous Silicon Dioxide)

Iron-stained quartz-rich rock (possibly weathered quartz vein material)

Quartz-rich, iron-oxide-stained rock; exact lithology cannot be determined from the photograph

Weathered conglomerate pebble

Polymictic conglomerate, likely quartz- and feldspar-rich clasts in a cemented matrix

Rounded, foliated metamorphic pebble (likely schist)

Mica schist, composition uncertain from the image

Chalcedony-rich agate/jasper

Microcrystalline quartz (SiO₂), likely iron-stained jasper with chalcedony

Olivine in Quartz/Feldspar Matrix (Peridotite or Granitic Pegmatite)

(Mg,Fe)2SiO4 (Olivine) with Quartz / Feldspar

Banded Iron Formation (Jaspilite / Hematite Jasper)

SiO2 + Fe2O3 (Quartz with Hematite/Magnetite)

Aquamarine (blue beryl)

Beryl, Be₃Al₂Si₆O₁₈; blue variety colored mainly by iron

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

Rounded, weathered rock (likely quartz-rich granite or gneiss)

Undetermined quartz–feldspar-rich rock; precise identification requires closer examination

Granite pebble

Granite, chiefly quartz, potassium feldspar, and plagioclase, with dark biotite or amphibole

Likely weathered limestone

Calcite-rich limestone (mostly CaCO₃), possibly dolomitic limestone

Porphyritic granite pebble

Granite, chiefly quartz (SiO₂), alkali feldspar and plagioclase, with minor biotite/hornblende

Quartz-rich conglomeratic sandstone

Lithic arkose/conglomerate, dominated by quartz and feldspar grains

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Desert Rose (Gypsum Rose)

Gypsum (CaSO4·2H2O) with inclusions of sand

Granitic Quartz or Pegmatite

Quartz with Orthoclase Feldspar (SiO2 + KAlSi3O8)

Gneiss

Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)

Paving-concrete aggregate with a rounded stone

Polymictic gravel aggregate; the central clast appears to be weathered sandstone or volcanic rock

Mixed rock and mineral gravel collection

Polymictic alluvial gravel; visible components likely quartz/quartzite, granite, basalt, limestone, and colored chalcedony or glassy minerals

Tumbled quartz-rich stone, possibly milky quartz or calcite

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

Weathered iron-rich rock, possibly hematite-bearing breccia

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

Mixed rounded rock and mineral gravel

Predominantly weathered basalt, quartz-rich fragments, and iron-stained silicate rocks; exact species cannot be determined reliably from the image

Tumbled jasper, likely ocean or brecciated jasper

Microcrystalline quartz (SiO₂) with iron-oxide and other mineral impurities