Man Made Material, Not A Natural Rock Or Mineral Specimen

Chert / Flint

Chert (Silicon Dioxide, SiO2)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Quartz Pebble

Silicon Dioxide (SiO2)

Chalcedony (Agate/Carnelian precursor)

Chalcedony (Silicon Dioxide, SiO2)

Ferruginous Sandstone (Ironstone Nodules)

Ferruginous Quartz-Arenite (with Goethite/Hematite cement)

Jasper

Silicon dioxide (SiO2)

Quartz / Milky Quartz

Silicon Dioxide (SiO2)

Olivine in Basalt (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4 (Mineral) / Scoriaceous Basalt (Host Rock)

Gneiss (River Cobble)

Gneiss (Foliated Metamorphic Rock)

Pink Granite

Granite (Phaneritic intrusive igneous rock)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Diamond Plate (Steel)

Alloyed Carbon Steel or Aluminum with 'Durbar' pattern

Granite with Quartz Vein

Phaneritic Felsic Igneous Rock (composed of Quartz [SiO2], Feldspar, and Mica)

Granite

Granite (Felsic intrusive igneous rock)

Bicolor Quartz (Milk Quartz with Slag or Dark Inclusions)

Silicon Dioxide (SiO2) with impurities

Fuchsite on Quartz

Muscovite (KAl2(AlSi3O10)(OH)2) with Chromium impurities

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Red Sandstone

Clastic Terrigenous Sedimentary Rock (typically Hematitic Quartz Arenite or Arkose)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Amber (Rough Baltics/Beach Specimen)

Succinicum (Organic Gemstone - Fossilized Resin)

Granite Pebble

Granite (a plutonic igneous rock composed primarily of quartz, feldspar, and mica/amphibole)

Charoite

Charoite (Hydrated potassium sodium calcium barium strontium silicate hydroxyfluoride)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Limonite/Hematite inclusions

Quartz Pebble (River Rock)

Silicon Dioxide (SiO₂)

Vesicular Basalt with Amygdules

Amygdaloidal Basalt

Chalcedony (Botryoidal or Agate nodule)

Silicon Dioxide (SiO2)

Diamond (set in Gold)

Diamond (pure carbon, C)

Basalt (with possible weathering or secondary mineral crust)

Basalt (Aphanitic Mafic Igneous Rock)

Basalt (with possible mineral veining)

Basalt (Aphanitic Mafic Igneous Rock)

Milky Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Diorite

Intrusive Igneous Rock (Intermediate Composition)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Marble

Recrystallized Calcite Rock (CaCO3)

Quartz Pebble

Silicon Dioxide (SiO2)

Conglomerate

Conglomerate (a clastic sedimentary rock)

Chrysocolla in Matrix

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Silicate/Secondary Copper Mineral)

Okenite (in Zeolite matrix)

Okenite (CaSi2O5 · 2H2O)

Quartz (Iron-Stained)

Silicon Dioxide (SiO2)

Prehnite

Ca2Al(AlSi3O10)(OH)2 (Calcium Aluminum Silicate hydroxide)