Sedimentary Or Metamorphic (Base Substrate)

Sandstone (Sedimentary Rock)

Arenite (SiO2 based)

Bloodstone

Chalcedony variety Heliotrope (SiO2 with inclusions)

Sandstone pebble

Sandstone (siliciclastic sedimentary rock)

Quartzite Pebble

Quartzite (primarily SiO2)

Sandstone

Arenite (SiO2 based)

Sandstone

Arenite (SiO2 based)

Sandstone

Arenite (SiO2 based)

Mica Schist

Mica Schist (predominantly Muscovite or Biotite)

Fuchsite

Chromium-bearing Muscovite - K(Al,Cr)2(AlSi3O10)(OH)2

Shale or Mudstone (Based on appearance)

Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)

Citrine

Citrine (Silicon Dioxide, SiO2)

River Stone (Sandstone or Siltstone)

Sedimentary Rock (Clastic)

Schist

Mica Schist

Limestone (Micritic)

Sedimentary rock mainly composed of Calcium Carbonate (CaCO3)

Muscovite Mica

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

Biotite Schist (with Garnet and Pyrite)

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

Breccia

Clastic Breccia

Orange Quartzite (Tumble-polished)

Quartzite (primarily SiO2)

Gravel and Sand Aggregate

Unconsolidated Clastic Sediment

Gravel

Unconsolidated rock fragments / detrital sediment

Sandstone

Arenite (mainly SiO2 with varying cements)

Chert (Flint Pebbles)

Microcrystalline Quartz (SiO2)

Pebble

Lithic fragment / Weathered rock fragment

Chert

Chert (SiO2)

River Cobble (Mixed Lithology)

Clastic Sedimentary Rock (Silicified Siltstone or Wacke)

Limestone (Decorative Gravel)

Calcium Carbonate (CaCO3)

Fuchsite

Chromian Muscovite, K(Al,Cr)2(AlSi3O10)(OH)2

Amethyst or Smoky Quartz Geode Slice

Crystalline Silicon Dioxide (SiO2) with iron impurities

Quartzite

Quartzite (SiO2-rich metamorphic rock)

Muscovite

Muscovite (KAl2(AlSi3O10)(OH)2)

Fuchsite

K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)

Muscovite Mica

Muscovite: KAl2(AlSi3O10)(OH)2

Biotite schist (probable mica schist)

Mica schist; chiefly quartz, biotite mica, and feldspar

Quartzite (Aventurine type)

Metamorphosed Quartz Sandstone (SiO2 with inclusions)

Shungite

Non-crystalline carbon (Fullerenes / Carbon-60)

Quartzite

Quartzite (SiO2)

Greenstone / Greenschist

Chlorite schist / Epidiorite / Metabasalt

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Greenstone

Metabasalt / Chlorite-Epidote Schist

Quartz with Muscovite Mica

Silicon Dioxide (SiO2) with Potassium Aluminum Silicate Hydroxide Fluoride (KAl2(AlSi3O10)(F,OH)2)

Polygenetic Conglomerate (or Breccia)

Clastic Sedimentary Rock

Sandstone (likely Arkose or Lithic)

Clastic sedimentary rock (SiO2 + impurities)