Antropogenic (Man Made Glass Byproduct)

Granite

Granite (Phaneritic Igneous Rock)

Granite Pebble

Igneous Intrusive Rock (Quartz-Feldspar-Mica Phenocrysts)

Olivine in Basalt matrix

Peridotite (Mg, Fe)2SiO4

Brown Sandstone Pebble

Clastic Sandstone (SiO2 with iron oxides)

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Granite

Felsic Plutonic Rock (Granite)

Smoky quartz

Quartz (SiO₂), naturally irradiated brown variety

Pegmatitic granite, possibly potassium-feldspar-rich

Coarse-grained granite; mainly quartz (SiO₂), potassium feldspar (KAlSi₃O₈), plagioclase, and biotite/hornblende

Tumbled milky quartz (likely quartz pebble)

Quartz, silicon dioxide (SiO₂)

Quartz Vein in Matrix

Silicon Dioxide (SiO2) within Rhyolitic or Granitic Matrix

Tumbled Amethyst

Quartz (SiO2) with trace amounts of Iron (Fe)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Banded sandstone pebble

Quartz-rich lithic sandstone; exact provenance and composition require testing

Tumbled reddish-brown pebble, likely sandstone or iron-rich quartzite

Probable ferruginous sandstone (quartz-rich; SiO₂ with iron oxides), possibly quartzite

Quartz-rich pegmatite or quartz vein rock

Mostly quartz (SiO₂), with probable feldspar and iron-oxide staining

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, possibly with mica or iron-oxide impurities

Chert (Black Chert/Flint)

Silicon Dioxide (SiO2)

Clear Quartz (Faceted) or Cubic Zirconia / Glass imitation

SiO2 (if Quartz), ZrO2 (if Cubic Zirconia)

Granite Cobble

Phaneritic Felsic Igneous Rock

Purple fluorite specimen

Fluorite (calcium fluoride, CaF₂)

Possible iron-rich chert or slag-like rock

Microcrystalline quartz (SiO₂), possibly iron-stained chert; exact identification is uncertain from the image

Granite

Granite (a felsic intrusive igneous rock)

Coarse-grained mica-bearing metamorphic rock, likely schist

Mica schist, probably muscovite–biotite schist with quartz and feldspar

Quartz-rich metamorphic fragment (likely mica schist)

Mica schist, probably muscovite–quartz schist

Raw greenish-blue quartz-bearing mineral specimen

Likely fluorite or chalcedony/quartz; exact identification requires hardness and crystal tests

Milky quartz

Quartz (silicon dioxide, SiO₂)

Sandstone (Weathered / Crushed)

Quartz Sandstone

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz pebble

Silicon Dioxide (SiO2)

Vesicular volcanic rock, possibly weathered basalt or scoria

Basaltic scoria/vesicular basalt; predominantly plagioclase, pyroxene, and iron-titanium oxides

Rounded basalt pebble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with minor olivine or magnetite

Granite

Plutonic felsic igneous rock

Granite

Phaneritic plutonic rock (SiO2-rich)

Granite

Plutonic felsic igneous rock

Granite

Granite (Felsic Plutonic Rock)

Limestone with Fossil Inclusion

Sedimentary Calcium Carbonate (CaCO3)

Granite

Phaneritic Felsic Igneous Rock

Smoky quartz fragment

Quartz, silicon dioxide (SiO₂), smoky variety

Greenstone (likely serpentinite or greenstone pebble)

Serpentinite-rich ultramafic rock; commonly dominated by serpentine-group minerals, with possible chlorite, actinolite, or magnetite

Dark fine-grained rock, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with olivine and iron oxides