Organic Material (Likely A Fruit Or Berry)

Biotite (Black Mica)

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

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone

Arenite (primarily SiO2 with various cementing agents)

Pearl

Calcium Carbonate (CaCO3) with Conchiolin

Aventurine and Amazonite

Silicon Dioxide (SiO2) with inclusions and Microcline (KAlSi3O8)

Amazonite (with smoky quartz/feldspar inclusions)

K(AlSi3O8), Microcline (Tectosilicate)

Quartzite (or Ferruginous Quartz)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Sandstone (Ferruginous)

Arenite (SiO2 with Fe2O3 inclusions)

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Aragonite

Aragonite (CaCO3)

Basalt (Weathered River Stone)

Basalt (Extrusive Mafic Igneous Rock)

Chert (and Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Biotite Schist (with Garnet and Pyrite)

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

Milky Quartz with Iron Inclusions

Quartz (Silicon Dioxide, SiO2)

Pink Granite

Phaneritic Plutonic Felsic Rock (Granite)

Amber

Succinite (fossilized tree resin)

Basalt with Epidote/Chlorite

Amygdaloidal Basalt (SiO2 with (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)))

Chert (with Limestone and Iron Oxide staining)

Cryptocrystalline Quartz (SiO2)

Jasper

Silicon Dioxide (SiO2)

River Quartz Pitting/Cobble

Silicon Dioxide (SiO2)

Osumilite in Granite Matrix

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

Quartzite Pebble (with Iron Inclusions)

Metamorphic Rock (Mainly SiO2)

Raw Citrine

Citrine (Silicon Dioxide - SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Yellow Quartzite Pebble

Quartzite (SiO2 with Iron Oxide staining)

Sandstone (Weathered Cobble)

Clastic Sedimentary Rock (primarily SiO2)

Pink Granite with Quartz Vein

Phaneritic Plutonic Felsic Rock (K-feldspar + Quartz + Plagioclase + Mica)

Limestone (Flagstone)

Fossiliferous Limestone (CaCO3)

Emerald with Matrix (Emerald in Mica Schist)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Pearl

Aragonite / Calcium Carbonate (CaCO3)

Amber

Succinite (fossilized tree resin), C10H16O

Gold (in Opaque Matrix/Jewelry)

Native Gold (Au)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Basalt (Lava Rock) and Dyed Glass/Quartz

Scoria (Vesicular Basalt)

Sandstone (Quartz-rich)

Arenite (composed primarily of SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Precious Red Coral

Corallium rubrum (Calcium Carbonate, CaCO3)

Yellow Quartzite (Onyx Pebble)

Silicon Dioxide (SiO2) - Quartzite

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Limestone (Fossiliferous)

Calcium Carbonate (CaCO3) - Bioclastic Limestone

Cream Marble (Speckled)

Metamorphosed Limestone (mainly CaCO3)

Quartz pebble (Quartztite fragment)

Silicon Dioxide (SiO2)