Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Category
Mineral_rock
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Polished serpentine pebble
Serpentinite, chiefly serpentine-group minerals (chrysotile, lizardite, antigorite)
metamorphic
Weathered metamorphic pebble, likely greenstone
Probable greenschist or chlorite-rich metabasalt; exact identification requires testing
metamorphic
Fluorite
Calcium fluoride (CaF2)
mineral
Milky quartz with iron-oxide staining
Quartz (SiO₂), likely massive milky quartz; minor limonite/goethite staining
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Weathered foliated metamorphic rock, likely schist or gneiss
Micaceous quartz–feldspar metamorphic rock; exact mineralogy requires testing
metamorphic
White quartz pebble
Quartz (silicon dioxide, SiO₂)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Limonite (Ironstone Concretion)
Limonite: FeO(OH)·nH2O
sedimentary
Pegmatitic granite, strongly weathered
Granite/pegmatite composed mainly of quartz, feldspar, and mica
igneous
Milky Quartz with Country Rock contact
Silicon Dioxide (SiO2) in contact with Metamorphic/Igneous rock
mineral
Milky quartz fragment
Quartz, silicon dioxide (SiO₂)
mineral
Red-brown jasper pebble
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
mineral
Quartz-rich pegmatite fragment
Granite-family pegmatite; chiefly quartz (SiO₂), feldspar, and black mica (biotite)
igneous
Blue Apatite
Apatite (Ca5(PO4)3(F,Cl,OH))
mineral
Chrysocolla
Hydrated copper phyllosilicate, (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Gneiss (River Cobble)
Gneiss
metamorphic
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Weathered, veined rock fragment (likely granite or gneiss)
Probable granitic gneiss; quartz–feldspar–mica assemblage
igneous
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
mineral
Sandstone
Arenite (SiO2 dominant)
sedimentary
Limonite (Iron Ore)
Limonite; FeO(OH)·nH2O
mineral
River Rock / Stream Pebble
Fluvial Clast / Rounded Sedimentary Particle
Sedimentary Rock (possibly composed of various minerals)
Banded Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Epidote
Calcium aluminum iron silicate (Ca2(Al, Fe)3(SiO4)3(OH))
mineral
Dinosaur Bone
Agatized Dinosaur Bone
sedimentary/fossil
Veined Basalt River Stone
Basalt with Calcite or Quartz veining
igneous
Sandstone
Arenite (lithic or quartz sandstone)
sedimentary
Weathered quartz-rich rock, possibly quartzite or silicified sandstone
Quartz-dominant aggregate; likely microcrystalline quartz (SiO₂), but exact identification requires testing
metamorphic
Lapis Lazuli
Lapis Lazuli (Complex aggregate mainly of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Greenstone / Epidosite
Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)
metamorphic
Quartz geode
Microcrystalline quartz and drusy quartz (SiO₂), commonly lining a chalcedony-rich cavity
mineral
River Cobble (Quartz-rich Sandstone)
Arenite with iron oxide staining
sedimentary
Granite (Gneissic / Weathered Pebble)
Felsic intrusive igneous rock (Granite)
igneous
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Quartz Vein / Quartz Matrix
Silicon Dioxide (SiO2)
mineral
Polished granite pebble
Granite; chiefly quartz, feldspar, and mica/amphibole
igneous