Sedimentary Or Igneous (Host Environment)

Basalt with Quartz/Feldspar Vein

Mafic Volcanic Rock (Basalt) with SiO2 hydrothermal vein

Amethyst-rich vesicular volcanic rock (probable amethyst basalt/scoria)

Quartz (SiO₂) in vesicular basaltic volcanic rock; precise identification requires testing

Quartz crystals on Basalt

SiO2 (Quartz) on Mafic Igneous Rock (Basalt)

Calcite in Matrix

Calcium Carbonate (CaCO3) on Sedimentary Host Rock

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Red Shale

Lutite (primarily composed of Hydrous Aluminum Silicates with Hematite staining)

Iron-stained quartz-rich rock, possibly smoky quartz

Quartz (SiO₂), likely with iron-oxide staining and dark inclusions; exact identification is uncertain from the photo

River Pebble (Gneiss or Quartzite variant)

Metamorphic rock specimen (likely Quartzite or Gneiss)

Limestone

Calcareous sedimentary rock (CaCO3)

Gold-colored gemstone ring, likely citrine or glass imitation

Indeterminate from image; possible quartz (SiO₂) or yellow glass set in gold-colored metal

Gneiss

Gneiss

Dark metamorphic rock, likely biotite schist or gneiss

Quartz–feldspar–biotite metamorphic rock; exact identification requires a fresh surface and testing

Iron-stained quartz (likely quartzite or quartz-rich rock)

Quartz, silicon dioxide (SiO₂), with iron-oxide staining

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Quartz-bearing metamorphic rock, likely schist or quartzite

Quartz (SiO₂) in a mica-rich metamorphic matrix

Likely mica schist

Mica-rich schist, probably biotite–quartz–feldspar schist

River Rock (Basalt or Sandstone)

Clastic Sedimentary Rock or Extrusive Mafic Igneous Rock

Milky Quartz

Silicon Dioxide (SiO2)

Cryptocrystalline Quartz (Agate/Chert)

Silicon dioxide (SiO2)

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Small white quartz fragment

Quartz (silicon dioxide, SiO₂)

Quartz (Milky Quartz)

Silicon Dioxide (SiO₂)

Quartz-rich pegmatite (possibly tourmaline-bearing)

Granitic pegmatite; chiefly quartz (SiO₂), feldspar, and dark mica/amphibole

Druzy Quartz on Vesicular Basalt

Silicon Dioxide (SiO2) in an extrusive Mafic igneous host rock

Quartz vein in weathered host rock

Milky quartz (SiO₂), likely in a feldspathic or carbonate-rich matrix

Potassium Feldspar

Orthoclase (KAlSi3O8)

Chalcedony Geode (Botryoidal Agate)

Silicon Dioxide (SiO2)

White Agate (Chalcedony)

Silicon Dioxide (SiO2)

Chalcopyrite in River Pebble (Pebble with Pyrite/Fool's Gold inclusions)

CuFeS2 in fine-grained igneous host rock (Basalt / Andesite)

Pyrite in Matrix (Healers Gold / Pyrite Egg)

Iron Disulfide (FeS2) with Magnetite/Hematite matrix

Banded Agate (Banded Chert / Jasper)

Silicon Dioxide (SiO2)

Tumbled Chalcedony Pebble

Silicon Dioxide (SiO2)

Calcite on Host Rock

Calcium Carbonate (CaCO3)

Geode or Concretion

Silica-based Concretion / Quartz Geode

Likely quartz-rich stone or shell fragment

Uncertain; possibly quartz (SiO₂) or a calcareous shell fragment (CaCO₃)

Weathered quartz-bearing metamorphic rock, likely gneiss or quartzite

Quartz-rich gneiss/quartzite with feldspar, mica, and iron-oxide alteration

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Greenstone / Serpentinite

Serpentine-group / Altered Mafic Rock

Weathered metamorphic rock, possibly schist or gneiss

Indeterminate; likely quartz–feldspar–mica rock, potentially greenschist or gneiss

Chert (specifically Flint Arrowhead)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Quartz with Host Rock

Silicon Dioxide (SiO2)