Mineral, Part Of A Rock

Basalt Pebble

Basalt

Riverstone (likely Graywacke or Siltstone)

Sedimentary sandstone (Graywacke), SiO2 dominant

Small white rounded mineral grain, likely quartz

Quartz (SiO₂), probable milky or vein quartz

Quartzite Pebble (River Rock)

Quartzite (primarily SiO2)

Granite (Weathered)

Grano-diorite / Granite (SiO2 rich intrusive rock)

Pyromorphite on Epidote

Pyromorphite [Pb5(PO4)3Cl] and Epidote [Ca2(Al2,Fe3+)(SiO4)3(OH)]

Red Quartz

Silicon Dioxide (SiO2) with Hematite inclusions

Quartz pebble

SiO2

Quartz Pebble

Silicon Dioxide (SiO2)

Feldspar Granodiorite

Granodiorite (Na,Ca)(Si,Al)4O8

Weathered Quartzite or Chert Pebble

Silicon Dioxide (SiO2)

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Speckled granitic rock, likely granite or granodiorite

Granite–granodiorite; mainly quartz (SiO₂), feldspars, and dark mica/amphibole

Granite

Phaneritic plutonic rock (Quartz, Feldspar, Mica)

Biotite / Black Mica

K(Mg,Fe)3(AlSi3O10)(F,OH)2

Garnet in Schist (Mica Schist with Garnet Inclusion)

Garnetiferous Mica Schist (X3Al2(SiO4)3)

Weathered granitic rock fragment

Likely granite or granodiorite; quartz–feldspar–mica aggregate

Rounded light-colored pebble, likely quartz-rich sandstone or quartzite

Unidentified quartz-rich rock; exact identification requires close examination or testing

Weathered quartz-bearing rock, possibly granite or granitic pegmatite

Indeterminate quartz–feldspar rock; exact identification requires a closer image or testing

Greenschist (Greenstone River Pebble)

Greenschist (Chlorite Schist)

Schist

Mica Schist

Osumilite in Granite Matrix

(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Labradorite

(Ca, Na)(Al, Si)4O8

River Pebble (Basalt or Gabbro)

Mafic Igneous Rock

Garnet (Pyrope or Almandine)

Silicate (X3Y2Si3O12)

Labradorite

Labradorite ((Ca,Na)(Al,Si)4O8)

Gneiss

Gneiss

Fossilized Syringopora (Piping Organ Coral)

Syringopora (Extinct Genus of Tabulate Coral)

Glauconite (Greensand)

Glauconite ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)

Small clear crystal, probably quartz

Quartz (SiO₂), possibly a tiny quartz chip or translucent feldspar fragment

Polished pink-and-gray granite

Granite, chiefly quartz, potassium feldspar, plagioclase, and biotite/hornblende

Polished leopard jasper (likely orbicular/rhyolitic jasper)

Silicified volcanic rock, mainly microcrystalline quartz (SiO₂), with iron-oxide and clay-rich inclusions

Granite

Plutonic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Diorite

Intrusive Igneous Diorite

Granite Cobble

Phaneritic Felsic Igneous Rock

Banded River Cobble with Mafic Dike

Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion

Fossilized shell or bone fragment

Indeterminate biogenic carbonate/phosphate fossil; likely a fragment of fossil shell or small vertebrate bone

Likely granite pebble

Granite, chiefly quartz, feldspar, and mica/amphibole

Granite Cobble

Phaneritic Felsic Igneous Rock (Granite)

Granite

Phaneritic plutonic felsic igneous rock

Polished agate or jasper cabochon

Microcrystalline quartz (chalcedony), chiefly SiO₂; exact variety is uncertain from the image