Manufactured Glass

Quartz on Matrix

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based)

Sandstone

Arenite (SiO2 based)

Sandstone (Quartzite-rich Pebble)

Arenite (primarily SiO2)

Sandstone

Arenite (SiO2 predominantly)

Sandstone (Quartz-rich)

Arenite

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite

Quartzite (SiO2)

Feldspar (Orthoclase)

Potassium Alveolar Silicate (KAlSi3O8)

Quartz (Milky/Clear Fragment)

Silicon Dioxide (SiO2)

Sandstone

Arenite (primarily SiO2)

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Muscovite Mica

Muscovite - KAl2(AlSi3O10)(F,OH)2

Quartz Pebble

Silicon dioxide (SiO2)

Tumbled yellow-green chalcedony or serpentine

Microcrystalline quartz (SiO₂), possibly chrysoprase; alternative: serpentine-group mineral

Quartz Crystal

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Milky Quartz in Epidote Host Rock

Crystalline Silicon Dioxide (SiO2) with Epidote Ca2(Al,Fe)3(SiO4)3(OH)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite river pebble

Quartzite (SiO2)

Blue slag glass or dyed glass-like industrial material

Amorphous silicate glass; likely copper-bearing blue slag, but possibly colored man-made glass

Polished fossil-bearing shale or mudstone

Fossiliferous carbonaceous mudstone/shale; visible fossils may be bivalves or ammonites, but species cannot be confirmed from the image

Weathered limestone pebble

Limestone, chiefly calcite (CaCO₃)

Dragon Vein Agate

Silicon Dioxide (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Sand Grain (Quartz)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Quartz (Silicon Dioxide, SiO2)

Quartzite Pebble

Quartzite (primarily SiO2)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Milky quartz

Quartz (SiO₂)

Quartz Pebble

Silicon Dioxide (SiO2)

Potassium Feldspar (Orthoclase Pebble)

KAlSi3O8 (Potassium aluminum silicate)

Pink feldspar crystal

Likely potassium feldspar (orthoclase or microcline), KAlSi₃O₈

Tumbled feldspar-rich rock, likely pink-orange microcline or granite fragment

K-feldspar (microcline/orthoclase), approximately KAlSi₃O₈; exact identification requires testing

Quartzite

Quartzite (mostly SiO2)

Quartzite

Quartzite (primarily SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Sandstone

Arenite (composed primarily of SiO2)