Man Made Material, Not A Natural Rock Or Mineral Specimen

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone (likely Quartzose Sandstone with mineral staining)

Arenite (composed mainly of SiO2)

Diamond

Diamond (C)

Citrine

Silicon Dioxide (SiO2) with iron impurities

Citrine Quartz Sphere

Silicon Dioxide (SiO2)

Chert (with Quartz Vein)

Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)

Unidentified Rock Fragment

Unknown

Muscovite Mica

Muscovite (Potassium Aluminum Silicate Hydroxide Fluoride), KAl2(AlSi3O10)(OH,F)2

Amygdaloidal Basalt

Amygdaloidal Basalt (extrusive volcanic rock with mineral inclusions)

Ferruginous Sandstone

Arenite with Iron-Oxide cement (primarily Fe2O3 • nH2O)

Vesicular Basalt

Mafic Volcanic Rock (Basalt)

Prasiolite (Green Quartz)

Silicon Dioxide (SiO2) with iron impurities

Quartz Pebble

Silicon Dioxide (SiO2)

Carnelian (Chalcedony)

Cryptocrystalline Quartz (SiO2) with Iron Oxide impurities

Red Shale

Fissile Siliciclastic Sedimentary Rock

Quartz Pebble

Silicon Dioxide (SiO2)

Fossilized Bone Fragment

Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)

Mica Schist

Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)

Sandstone Beach Pebble

Clastic Sandstone (SiO2 - Quartz-dominant)

Septarian Nodule Segment (Turtle Stone)

Septarian Concretion (CaCO3 with Siderite or Calcite infill)

Quartz Pebble

Silicon Dioxide (SiO2)

Jasper in Basalt Matrix

Silicon Dioxide (SiO2) with impurities; Chalcedony

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble (with Manganese dendrites/staining)

Silicon Dioxide (SiO2) with Manganese Oxide impurities

Labradorite

(Ca, Na)(Al, Si)4O8

Quartzite (Milky Quartz pebble)

Silicon Dioxide (SiO2)

Amethyst Geode (polished heart-cut)

Silicon Dioxide (SiO2) with iron impurities

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3 iron oxide staining)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Sandstone with Foliose Lichen

Arenite (Rock matrix) with Xanthoparmelia or Flavoparmelia (Lichen genus)

Basalt with Scoria/Vesicular Texture

Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Fluorite in Matrix

Fluorite (CaF2) within a host rock matrix

Granite

Phaneritic Plutonic Felsic Rock

Schist

Mica Schist (primarily Muscovite [KAl2(AlSi3O10)(OH)2] or Biotite)

Quartz Pebble

Silicon Dioxide (SiO2)

Crazy Lace Agate

Silicon Dioxide (SiO2) with impurities

Halite (Rock Salt)

Halite; NaCl (Sodium Chloride)

Quartz

Quartz (SiO2, Silicon Dioxide)

Common Opal with Host Rock

Opal (Hydrated silica, SiO2·nH2O)