Mineralological Specimen

Basalt River Pebble

Mafic Igneous Rock (Fine-grained Basalt)

Glauconitic Sandstone (Greenstone)

Glauconitic Siliciclastic Sandstone (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2

Porphyry

Porphyritic Andesite/Basalt

Quartzite

Quartzite (primarily SiO2)

Banded Chert or Chert with Quartz Veins

Chert (SiO2)

Silicon Carbide (Carborundum)

Silicon Carbide (SiC)

Basalt (Weathered/River worn)

Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)

Basalt (Porphyritic Basalt)

Porphyritic Basalt (Mafic volcanic rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Hematite

Hematite (Fe2O3)

Labradorite

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

Green Apophyllite

Fluorapophyllite-(K), KCa4(Si8O20)(F,OH)·8H2O

Banded Agate

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Quartz Pebble

Silicon Dioxide (SiO2)

Jasper (Iron-stained Quartzite/Chert)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) impurities

Concrete Fragment

Hardened Portland Cement Composite

Chert (Jasper)

Silicon Dioxide (SiO2)

Quartzite (River Cobble)

Metamorphosed Quartz Sandstone (SiO2)

Granite (River-worn Cobble)

Phaneritic Felsic Igneous Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Granite

Granite (Phaneritic Acidic Igneous Rock)

Chalcedony (Quartz Nodule)

Silicon Dioxide (SiO2)

Sandstone (Quartzose Sandstone)

Clastic sedimentary rock (SiO2 major component)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Quartzite Pebble

Quartzite (primarily SiO2)

Yellow Chalcedony (Agate Pebble)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Granite Cobble (River Stone)

Felsic intrusive igneous rock (composition: Quartz, Feldspar, Mica)

Milky Quartz

Silicon Dioxide (SiO2)

Basalt (with possible mineral veining)

Basalt (Aphanitic Mafic Igneous Rock)

Clear Quartz Sphere

Silicon Dioxide (SiO2)

Pink Granite (River Pebble)

Phaneritic Felsic Igneous Rock

Quartzite (River Pebble)

Quartzite (SiO2)

Jasper and Chert Conglomerate

Ferruginous Microcrystalline Quartz (SiO2)

River Cobble (Salt and Pepper Gneiss)

Gneiss (High-grade regional metamorphic rock)

Granite Cobble

Phaneritic Felsic Igneous Rock (Granite)

Basalt (Crushed Roadstone)

Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Jasper / Chert (River Pebble)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (often called Jasper or River Siltstone)

Microcrystalline Quartz (SiO2)

Chert (Iron-stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Ferruginous Sandstone (Ironstone Nodules)

Ferruginous Sandstone with Limonite/Goethite coating (Fe2O3·H2O)

Milky Quartz (with Iron staining)

Silicon Dioxide (SiO2)

Orange Quartzite / Carnelian Agate

Silicon Dioxide (SiO2)