Sedimentary (Secondary Classification For A Weathered Mineral Specimen)

Sandstone Pebble (Quartzite-rich)

Clastic Terrigenous Sedimentary Rock (SiO2 dominant)

Red Granite

Phaneritic Felsic Igneous Rock

Milky Quartz

Silicon Dioxide (SiO2)

Granite

Phaneritic Felsic Igneous Rock (Granite)

Quartzite River Rock

Quartzite (primarily SiO2)

Agate (Bead Form)

Agate (Cryptocrystalline Quartz, SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Basalt

Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 with (Ca,Na)(Al,Si)4O8

Asphalt (Bituminous Concrete)

Composite material (bitumen binder with mineral aggregate)

Chrysoprase

Silicon dioxide with nickel impurities (SiO2 + Ni)

Petrified Wood

Silicified wood (primarily Quartz/Chalcedony, SiO2)

Moss Agate

Silicon Dioxide with inclusions (SiO2)

Basalt

Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (SiO2)

Chert (Field Stone)

Chert (SiO2)

Yellow Chert or Jasper

Microcrystalline Quartz (SiO2) with iron oxide inclusions

Chert Arrowhead

Microcrystalline Quartz (SiO2)

Jasper

Jasper (Silicate - SiO2)

Chert (specifically Blue Chert/Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Gold Nugget

Native Gold (Au)

Chert (Grey-Green Flint)

Microcrystalline silicon dioxide (SiO2)

Granite with Biotite and Quartz

Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, and K(Mg,Fe)3AlSi3O10(OH)2)

Gold

Gold (Native Element); Au

Petrified Wood

Silicified Wood (SiO2)

Jasper and Quartz River Cobble

Silicon Dioxide (SiO2) with Hematite inclusions

Chert (Nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Milky Quartz

Silicon Dioxide (SiO2)

Granite (Dioritic or Hornblende-rich)

Phaneritic Plutonic Felsic to Intermediate Igneous Rock

Ruby

Corundum (Al2O3 with Chromium traces)

Rough Ruby

Corundum (Al2O3 with Chromium impurities)

Pumice or Tufa/Travertine

Pumice (if igneous) or Calcareous Tufa (if sedimentary)

Chert (variations include Flint or Jasper)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Shale or Slate with Quartz Veins

Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins

Calamites Fossil (Horsetail Stem)

Calamites (Genus), part of the class Equisetopsida

Granite

Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, NaAlSi3O8)

Tourmaline (likely Schorl)

Tourmaline Group Mineral (e.g., Schorl for black varieties); (Na,Ca)(Li,Mg,Fe,Mn,Al)3Al6(BO3)3Si6O18(OH)4

Blue Sapphire

Corundum (Al2O3) with iron and titanium impurities

Fossiliferous Limestone

Bioclastic Limestone (composition: CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Chert (Jasper/Carnelian variety)

Microcrystalline Quartz (SiO2)