Mineral, Often A Rock Given Its Aggregate Nature

Quartzite (River Cobble)

SiO2 (Quartz-rich Metamorphic Rock)

Granite

Phaneritic high-silica plutonic rock (composed primarily of Quartz, Feldspar, and Mica)

Sandstone (Greywacke)

Clastic Sedimentary Rock (SiO2 with lithic fragments)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

White Jade (Nephrite)

Nephrite, Ca2(Mg,Fe)5Si8O22(OH)2

Jasper (Red Jasper)

Silicon Dioxide (SiO2) with Hematite inclusions

Blue Quartz

Quartz (SiO2) with inclusions

Scoria (Lava Rock)

Vesicular Basalt / Scoria

Milky Quartz

Silicon Dioxide (SiO2)

Chert (Nodular)

Chert (Microcrystalline Quartz, SiO2)

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Greywacke (River Siltstone)

Lithic Wacke (Sandstone subfamily)

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2)

Lapis Lazuli

Lapis Lazuli (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2

Basalt

Afanitic Mafic Basalt

Pink Granite

Phaneritic Felsic Igneous Rock (Granite)

Greywacke (River Siltstone)

Lithic Sandstone / Greywacke

Basalt

Basalt

Massive Quartz (Milky or Gray)

Silicon Dioxide (SiO2)

Basalt

Africite (Mafic Igneous Rock)

Druzy Quartz on Chert/Chalcedony

Silicon Dioxide (SiO2)

Howlite

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Chert (specifically Flint or Common Chert node)

Silicon Dioxide (SiO2)

White Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Andesite

Andesite (Intermediate Extrusive Volcanic Rock)

Conglomerate

Conglomerate (Clastic sedimentary rock)

Quartz

Quartz (SiO2)

Limestone (Porous/Travertine variant)

Sedimentary Calcium Carbonate (CaCO3)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Druzy)

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Basalt (Beach Pebble)

Basalt (Aphanitic Mafic Igneous Rock)

Serpentine, likely a variety of Chrysoprase (green chalcedony) or a similar translucent green mineral.

Serpentine Group Minerals (e.g., Antigorite, Lizardite) or Chalcedony (SiO2) with nickel impurities for Chrysoprase green.

Unakite

Epidotized Granite

Granite

Phaneritic Acidic Igneous Rock (Granite Group)

Jasper

Jasper (Silicon Dioxide, SiO2)

Amazonite

KAlSi3O8 (Potassium Feldspar, variety of Microcline)

Basalt (tumbled/river-worn)

Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)

Chert (specifically Yellow or River Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)