Sedimentary (Secondary Classification For A Weathered Mineral Specimen)

Pyrite

Iron Sulfide (FeS2)

Botryoidal Chalcedony

Silicon Dioxide (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Pyrite Geode (Sparkling Druzy)

Iron Sulfide (FeS2) in Sedimentary Nodule

Chalcedony (Agate/Jasper mix in host rock)

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Carnelian

SiO2 (Chalcedony with iron oxide impurities)

Sandstone (Micaceous/Feldspathic variant)

Arenite (specifically subarkose or lithic arenite)

Sandstone (Banded)

Clastic Sedimentary Rock (primarily SiO2)

Agate (specifically a Blue Agate Geode Slice)

Chalcedony (cryptocrystalline variety of Quartz); SiO2

Granite

Granite (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase Feldspar)

Polished Ocean Jasper

Orbicular Jasper (variety of Chalcedony/Quartz, SiO2)

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock with secondary mineral fillings)

Chert (containing a small fossil)

Microcrystalline Quartz (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Agate

Cryptocrystalline Quartz (SiO2)

Black Opal

Hydrated Silica (SiO2·nH2O)

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Extrusive)

Pyrite

Iron Sulfide (FeS2)

River Stone (Granitic Gneiss)

Foliated Granitic Gneiss

Dolomite on Prehnite (Saddle-shaped Dolomite)

Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]

Agate (specifically Moss or Plume Agate nodding toward Agatized Wood)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz (Chalcedony)

Optical Calcite (Iceland Spar)

Calcium Carbonate (CaCO3)

Hematite

Iron(III) oxide (Fe2O3)

Olivine in Basalt (Peridotite Xenolith)

Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt

Precious Opal

Hydrated Silica (SiO2·nH2O)

Diamond (in a cluster setting)

Crystallized Carbon (C)

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)

Porphyritic Basalt (Mafic volcanic rock)

Amygdaloidal Basalt

Amygdaloidal Basalt (Host rock) with Quartz or Calcite amygdules

Pyrite

Iron Sulfide (FeS2)

Green Jasper

Silicon Dioxide (SiO2) with impurities

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Chert (containing fossil leaf impression)

Microcrystalline silicon dioxide (SiO2)

Chert (Yellow/Tan variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Diamond

Native Carbon (C)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Chlorastrolite (Isle Royale Greenstone)

Chlorastrolite (Pumpellyite-(Mg,Al)), formula: Ca2(Mg,Fe)Al2(SiO4)(Si2O7)(OH)2∙H2O

Chert (variations include Flint/Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Granite (Dioritic variant)

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Chondrite Meteorite Fragment

Ordinary Chondrite (L or H type)

Agate (Beads)

Silicon Dioxide (SiO2)

Vanadinite

Lead Chlorovanadate - Pb5(VO4)3Cl