Mineral Like Biological Tissue

Basalt

Basalt (Mafic volcanic rock)

Basalt

Basalt

Sandstone (Quartz-rich)

Arenite (SiO2)

Sandstone (Ferruginous)

Arenite (Fe2O3 dominant staining)

Massive Quartz with Host Rock

Silicon Dioxide (SiO2)

Red Slag Glass

Amorphous Silica (Industrial byproduct with metallic oxide dopants)

Red Sandstone

Arenite (with Iron Oxide / Hematite cementation)

Sandstone

Arenite (variable SiO2 composition)

Smoky Quartz

Silicon Dioxide (SiO2)

Botryoidal Chalcedony (Agate/Desert Rose Chalcedony)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Black Tourmaline in Quartz

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4) in Silicon Dioxide (SiO2)

Chrysocolla in Matrix

Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·nH2O

Botryoidal Goethite on Quartz

Goethite (α-Fe3+O(OH)) on Quartz (SiO2)

Orbicular Rhyolite (Rainforest Jasper)

Rhyolite containing Spherulites (SiO2 with impurities)

Sandstone

Arenite (SiO2 primarily)

Tiger's Eye (dark/grey variant)

Pseudomorph of Quartz after Crocidolite (SiO2)

Quartz (likely milky/rose quartz variety)

Quartz (SiO2 - Silicon Dioxide)

Banded Agate (Lace Agate)

Agate (Variety of Cryptocrystalline Quartz), SiO2

Milky Quartz

Silicon Dioxide (SiO2)

Snowflake Obsidian

Volcanic glass containing Spherulitic Cristobalite (SiO2)

Quartz (Milky/Clear Variety)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (complex silicate composition with iron oxides)

Diorite (Salt and Pepper Rock)

Phaneritic Plutonic Diorite; chemical composition roughly 52-63% silica (SiO2)

Granite Pebble

Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Granite

Granite (composed primarily of Quartz SiO2 and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8))

Banded Gneiss

Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Biotite/Amphiboles)

Rose Quartz

Silicon dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Yellow Quartz (Citrine/Quartzite Pebble)

Silicon Dioxide (SiO2)

Banded Agate (Jasper-Agate)

Silicon Dioxide (SiO₂)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Honey Calcite

Calcium Carbonate (CaCO3)

Clear Quartz Cluster

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Smoky Quartz (Ferruginous Quartz)

Quartz (Silicon Dioxide, SiO2)

Cubic Zirconia (CZ)

Zirconium dioxide (ZrO2)

Almandine Garnet

Almandine [Fe3Al2(SiO4)3]

Chert (Arrowhead Preform or Flake)

Microcrystalline Quartz (SiO2)

Siderite Concretion (Nodule)

Iron Carbonate (FeCO3) Concretion

Yellow Aventurine (Quartz Quartzite)

Silicon Dioxide with Mica inclusions (SiO2 + KAl2(AlSi3O10)(OH)2)

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2)